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101月/16关

MySql数据库 sql查询增加序号的伪列

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在查询数据库的时候，我们有时候需要对查询出来的数据加上序列，1,2,3，……n

例如：我们根据表的某个字段排序后，要对这些数据加上序列，这个时候序号常常不是我们建表时设置好的自增的主键id，怎么办呢？？？？

可能我们会用变量来解决，如下

set @rownum=0;

SELECT @rownum:=@rownum+1 AS rownum, table_name.*
FROM  table_name

 

如果在数据库中要用一句SQL语句来实现，这又改怎么办呢？？？？

Oracle数据库有专门的rownum来解决伪序列问题，但是MySQL却到目前为止还没有内置的函数等来解决此问题

这个问题也困扰了我一段时间，到各种上发帖也没有能回答，最后在无意间找到了这种解决方法

 

SELECT @rownum:=@rownum+1 AS rownum, table_name.*
FROM (SELECT @rownum:=0) r, table_name

把rownum的设置初值放到了from 和需要查询的表的前面

原文来自“老鸟的大心脏”，在这里谢谢他。

希望能帮助更多需要帮助的人……

也希望更多的高手们提出更多的漂亮的方法……

也许有人也会用到存储过程来解决，那也是一个方法，我曾经也用过，但是后来不能用存储过程了，就悲剧了

摘自 ystyaoshengting的专栏

 

但是程序会报错“Parameter '@rownum' must be defined.”

这时在配置文件数据库链接串后面加上“Allow User Variables=True”,就好了

<!--mysql连接字符串-->
        <add key="MySqlConn" value="Server=192.168.1.238;DataBase=gm;Uid=root;Pwd=000000;Allow User Variables=True;"/>

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2212月/15关

MYSQL explain详解

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explain显示了mysql如何使用索引来处理select语句以及连接表。可以帮助选择更好的索引和写出更优化的查询语句。

先解析一条sql语句，看出现什么内容

EXPLAINSELECTs.uid,s.username,s.name,f.email,f.mobile,f.phone,f.postalcode,f.address
FROM uchome_space ASs,uchome_spacefieldASf
WHERE 1 
AND s.groupid=0
AND s.uid=f.uid

1. id

SELECT识别符。这是SELECT查询序列号。这个不重要,查询序号即为sql语句执行的顺序，看下面这条sql

EXPLAINSELECT*FROM(SELECT* FROMuchome_space LIMIT10)ASs

它的执行结果为

可以看到这时的id变化了

2.select_type

select类型，它有以下几种值

2.1 simple 它表示简单的select,没有union和子查询

2.2 primary 最外面的select,在有子查询的语句中，最外面的select查询就是primary,上图中就是这样

2.3 union union语句的第二个或者说是后面那一个.现执行一条语句，explain 
select * from uchome_space limit 10 union select * from uchome_space limit 10,10

会有如下结果

第二条语句使用了union

2.4 dependent union    UNION中的第二个或后面的SELECT语句，取决于外面的查询

2.5 union result        UNION的结果,如上面所示

还有几个参数，这里就不说了，不重要

3 table

输出的行所用的表，这个参数显而易见，容易理解

4 type

连接类型。有多个参数，先从最佳类型到最差类型介绍 重要且困难

4.1 system

表仅有一行，这是const类型的特列，平时不会出现，这个也可以忽略不计

4.2 const

表最多有一个匹配行，const用于比较primary key 或者unique索引。因为只匹配一行数据，所以很快

记住一定是用到primary key 或者unique，并且只检索出两条数据的 情况下才会是const,看下面这条语句

explain SELECT * FROM `asj_admin_log` limit 1,结果是

虽然只搜索一条数据，但是因为没有用到指定的索引，所以不会使用const.继续看下面这个

explain SELECT * FROM `asj_admin_log` where log_id = 111

log_id是主键，所以使用了const。所以说可以理解为const是最优化的

4.3 eq_ref

对于eq_ref的解释，mysql手册是这样说的:"对于每个来自于前面的表的行组合，从该表中读取一行。这可能是最好的联接类型，除了const类型。它用在一个索引的所有部分被联接使用并且索引是UNIQUE或PRIMARY KEY"。eq_ref可以用于使用=比较带索引的列。看下面的语句

explain select * from uchome_spacefield,uchome_space where uchome_spacefield.uid = uchome_space.uid

得到的结果是下图所示。很明显，mysql使用eq_ref联接来处理uchome_space表。

目前的疑问：

       4.3.1 为什么是只有uchome_space一个表用到了eq_ref,并且sql语句如果变成

       explain select * from uchome_space,uchome_spacefield where uchome_space.uid = uchome_spacefield.uid

       结果还是一样，需要说明的是uid在这两个表中都是primary

4.4 ref 对于每个来自于前面的表的行组合，所有有匹配索引值的行将从这张表中读取。如果联接只使用键的最左边的前缀，或如果键不是UNIQUE或PRIMARY KEY（换句话说，如果联接不能基于关键字选择单个行的话），则使用ref。如果使用的键仅仅匹配少量行，该联接类型是不错的。

看下面这条语句 explain select * from uchome_space where uchome_space.friendnum = 0，得到结果如下，这条语句能搜出1w条数据

4.5 ref_or_null 该联接类型如同ref，但是添加了MySQL可以专门搜索包含NULL值的行。在解决子查询中经常使用该联接类型的优化。

上面这五种情况都是很理想的索引使用情况

4.6 index_merge 该联接类型表示使用了索引合并优化方法。在这种情况下，key列包含了使用的索引的清单，key_len包含了使用的索引的最长的关键元素。

4.7 unique_subquery 

4.8 index_subquery

4.9 range 给定范围内的检索，使用一个索引来检查行。看下面两条语句

explain select * from uchome_space where uid in (1,2)

explain select * from uchome_space where groupid in (1,2)

uid有索引，groupid没有索引，结果是第一条语句的联接类型是range,第二个是ALL.以为是一定范围所以说像 between也可以这种联接,很明显

explain select * from uchome_space where friendnum = 17

这样的语句是不会使用range的，它会使用更好的联接类型就是上面介绍的ref

4.10 index     该联接类型与ALL相同，除了只有索引树被扫描。这通常比ALL快，因为索引文件通常比数据文件小。（也就是说虽然all和Index都是读全表，但index是从索引中读取的，而all是从硬盘中读的）

当查询只使用作为单索引一部分的列时，MySQL可以使用该联接类型。

4.11  ALL  对于每个来自于先前的表的行组合，进行完整的表扫描。如果表是第一个没标记const的表，这通常不好，并且通常在它情况下很差。通常可以增加更多的索引而不要使用ALL，使得行能基于前面的表中的常数值或列值被检索出。

5 possible_keys 提示使用哪个索引会在该表中找到行，不太重要

6 keys MYSQL使用的索引，简单且重要

7 key_len MYSQL使用的索引长度

8 ref   ref列显示使用哪个列或常数与key一起从表中选择行。

9 rows 显示MYSQL执行查询的行数，简单且重要，数值越大越不好，说明没有用好索引

10 Extra  该列包含MySQL解决查询的详细信息。

10.1 Distinct     MySQL发现第1个匹配行后，停止为当前的行组合搜索更多的行。一直没见过这个值

10.2 Not exists  

10.3 range checked for each record

没有找到合适的索引

10.4 using filesort    

MYSQL手册是这么解释的“MySQL需要额外的一次传递，以找出如何按排序顺序检索行。通过根据联接类型浏览所有行并为所有匹配WHERE子句的行保存排序关键字和行的指针来完成排序。然后关键字被排序，并按排序顺序检索行。”目前不太明白

10.5 using index 只使用索引树中的信息而不需要进一步搜索读取实际的行来检索表中的信息。这个比较容易理解，就是说明是否使用了索引

explain select * from ucspace_uchome where uid = 1的extra为using index（uid建有索引）

explain select count(*) from uchome_space where groupid=1 的extra为using where(groupid未建立索引)

10.6 using temporary

为了解决查询，MySQL需要创建一个临时表来容纳结果。典型情况如查询包含可以按不同情况列出列的GROUP BY和ORDER BY子句时。

出现using temporary就说明语句需要优化了，举个例子来说

EXPLAIN SELECT ads.id FROM ads, city WHERE   city.city_id = 8005   AND ads.status = 'online'   AND city.ads_id=ads.id ORDER BY ads.id desc

id  select_type  table   type    possible_keys   key      key_len  ref                     rows  filtered  Extra                          
------  -----------  ------  ------  --------------  -------  -------  --------------------  ------  --------  -------------------------------
     1  SIMPLE       city    ref     ads_id,city_id  city_id  4        const                   2838    100.00  Using temporary; Using filesort
     1  SIMPLE       ads     eq_ref  PRIMARY         PRIMARY  4        city.ads_id       1    100.00  Using where    

这条语句会使用using temporary,而下面这条语句则不会

 

EXPLAIN SELECT ads.id FROM ads, city WHERE   city.city_id = 8005   AND ads.status = 'online'   AND city.ads_id=ads.id ORDER BY city.ads_id desc

id  select_type  table   type    possible_keys   key      key_len  ref                     rows  filtered  Extra                      
------  -----------  ------  ------  --------------  -------  -------  --------------------  ------  --------  ---------------------------
     1  SIMPLE       city    ref     ads_id,city_id  city_id  4        const                   2838    100.00  Using where; Using filesort
     1  SIMPLE       ads    eq_ref  PRIMARY         PRIMARY  4        city.ads_id       1    100.00  Using where    

这是为什么呢？他俩之间只是一个order by不同，MySQL 表关联的算法是 Nest Loop Join，是通过驱动表的结果集作为循环基础数据，然后一条一条地通过该结果集中的数据作为过滤条件到下一个表中查询数据，然后合并结果。EXPLAIN 结果中，第一行出现的表就是驱动表（Important!）以上两个查询语句，驱动表都是 city，如上面的执行计划所示！

对驱动表可以直接排序，对非驱动表（的字段排序）需要对循环查询的合并结果（临时表）进行排序（Important!）
因此，order by ads.id desc 时，就要先 using temporary 了！
驱动表的定义
wwh999 在 2006年总结说，当进行多表连接查询时， [驱动表] 的定义为：
1）指定了联接条件时，满足查询条件的记录行数少的表为[驱动表]；
2）未指定联接条件时，行数少的表为[驱动表]（Important!）。

永远用小结果集驱动大结果集

 

今天学到了一个很重要的一点：当不确定是用哪种类型的join时，让mysql优化器自动去判断，我们只需写select * from t1,t2 where t1.field = t2.field

10.7 using where

WHERE子句用于限制哪一个行匹配下一个表或发送到客户。除非你专门从表中索取或检查所有行，如果Extra值不为Using where并且表联接类型为ALL或index，查询可能会有一些错误。（这个说明不是很理解，因为很多很多语句都会有where条件，而type为all或index只能说明检索的数据多，并不能说明错误，useing where不是很重要，但是很常见）

如果想要使查询尽可能快，应找出Using filesort 和Using temporary的Extra值。

10.8 Using sort_union(...), Using union(...),Using intersect(...)

这些函数说明如何为index_merge联接类型合并索引扫描

10.9 Using index for group-by

类似于访问表的Using index方式，Using index for group-by表示MySQL发现了一个索引，可以用来查询GROUP BY或DISTINCT查询的所有列，而不要额外搜索硬盘访问实际的表。并且，按最有效的方式使用索引，以便对于每个组，只读取少量索引条目。

实例讲解

 

通过相乘EXPLAIN输出的rows列的所有值，你能得到一个关于一个联接如何的提示。这应该粗略地告诉你MySQL必须检查多少行以执行查询。当你使用max_join_size变量限制查询时，也用这个乘积来确定执行哪个多表SELECT语句。

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116月/15关

MySQL Date and Time Functions

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Name Description
ADDDATE() Add dates
ADDTIME() Add time
CONVERT_TZ() Convert from one timezone to another
CURDATE() Return the current date
CURRENT_DATE(), CURRENT_DATE Synonyms for CURDATE()
CURRENT_TIME(), CURRENT_TIME Synonyms for CURTIME()
CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP Synonyms for NOW()
CURTIME() Return the current time
DATE_ADD() Add two dates
DATE_FORMAT() Format date as specified
DATE_SUB() Subtract two dates
DATE() Extract the date part of a date or datetime expression
DATEDIFF() Subtract two dates
DAY() Synonym for DAYOFMONTH()
DAYNAME() Return the name of the weekday
DAYOFMONTH() Return the day of the month (1-31)
DAYOFWEEK() Return the weekday index of the argument
DAYOFYEAR() Return the day of the year (1-366)
EXTRACT Extract part of a date
FROM_DAYS() Convert a day number to a date
FROM_UNIXTIME() Format date as a UNIX timestamp
HOUR() Extract the hour
LAST_DAY Return the last day of the month for the argument
LOCALTIME(), LOCALTIME Synonym for NOW()
LOCALTIMESTAMP, LOCALTIMESTAMP() Synonym for NOW()
MAKEDATE() Create a date from the year and day of year
MAKETIME MAKETIME()
MICROSECOND() Return the microseconds from argument
MINUTE() Return the minute from the argument
MONTH() Return the month from the date passed
MONTHNAME() Return the name of the month
NOW() Return the current date and time
PERIOD_ADD() Add a period to a year-month
PERIOD_DIFF() Return the number of months between periods
QUARTER() Return the quarter from a date argument
SEC_TO_TIME() Converts seconds to 'HH:MM:SS' format
SECOND() Return the second (0-59)
STR_TO_DATE() Convert a string to a date
SUBDATE() When invoked with three arguments a synonym for DATE_SUB()
SUBTIME() Subtract times
SYSDATE() Return the time at which the function executes
TIME_FORMAT() Format as time
TIME_TO_SEC() Return the argument converted to seconds
TIME() Extract the time portion of the expression passed
TIMEDIFF() Subtract time
TIMESTAMP() With a single argument, this function returns the date or datetime expression. With two arguments, the sum of the arguments
TIMESTAMPADD() Add an interval to a datetime expression
TIMESTAMPDIFF() Subtract an interval from a datetime expression
TO_DAYS() Return the date argument converted to days
UNIX_TIMESTAMP() Return a UNIX timestamp
UTC_DATE() Return the current UTC date
UTC_TIME() Return the current UTC time
UTC_TIMESTAMP() Return the current UTC date and time
WEEK() Return the week number
WEEKDAY() Return the weekday index
WEEKOFYEAR() Return the calendar week of the date (1-53)
YEAR() Return the year
YEARWEEK() Return the year and week
ADDDATE(date,INTERVAL expr unit), ADDDATE(expr,days)

When invoked with the INTERVAL form of the second argument, ADDDATE() is a synonym for DATE_ADD(). The related function SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().

mysql> SELECT DATE_ADD('1998-01-02', INTERVAL 31 DAY);
+---------------------------------------------------------+
| DATE_ADD('1998-01-02', INTERVAL 31 DAY) |
+---------------------------------------------------------+
| 1998-02-02 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT ADDDATE('1998-01-02', INTERVAL 31 DAY);
+---------------------------------------------------------+
| ADDDATE('1998-01-02', INTERVAL 31 DAY) |
+---------------------------------------------------------+
| 1998-02-02 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
When invoked with the days form of the second argument, MySQL treats it as an integer number of days to be added to expr.

mysql> SELECT ADDDATE('1998-01-02', 31);
+---------------------------------------------------------+
| DATE_ADD('1998-01-02', INTERVAL 31 DAY) |
+---------------------------------------------------------+
| 1998-02-02 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
ADDTIME(expr1,expr2)

ADDTIME() adds expr2 to expr1 and returns the result. expr1 is a time or datetime expression, and expr2 is a time expression.

mysql> SELECT ADDTIME('1997-12-31 23:59:59.999999','1 1:1:1.000002');
+---------------------------------------------------------+
| DATE_ADD('1997-12-31 23:59:59.999999','1 1:1:1.000002') |
+---------------------------------------------------------+
| 1998-01-02 01:01:01.000001 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
CONVERT_TZ(dt,from_tz,to_tz)

This converts a datetime value dt from the time zone given by from_tz to the time zone given by to_tz and returns the resulting value. This function returns NULL if the arguments are invalid.

mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');
+---------------------------------------------------------+
| CONVERT_TZ('2004-01-01 12:00:00','GMT','MET') |
+---------------------------------------------------------+
| 2004-01-01 13:00:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00');
+---------------------------------------------------------+
| CONVERT_TZ('2004-01-01 12:00:00','+00:00','+10:00') |
+---------------------------------------------------------+
| 2004-01-01 22:00:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
CURDATE()

Returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.

mysql> SELECT CURDATE();
+---------------------------------------------------------+
| CURDATE() |
+---------------------------------------------------------+
| 1997-12-15 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT CURDATE() + 0;
+---------------------------------------------------------+
| CURDATE() + 0 |
+---------------------------------------------------------+
| 19971215 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
CURRENT_DATE and CURRENT_DATE()

CURRENT_DATE and CURRENT_DATE() are synonyms for CURDATE()

CURTIME()

Returns the current time as a value in 'HH:MM:SS' or HHMMSS format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone.

mysql> SELECT CURTIME();
+---------------------------------------------------------+
| CURTIME() |
+---------------------------------------------------------+
| 23:50:26 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT CURTIME() + 0;
+---------------------------------------------------------+
| CURTIME() + 0 |
+---------------------------------------------------------+
| 235026 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
CURRENT_TIME and CURRENT_TIME()

CURRENT_TIME and CURRENT_TIME() are synonyms for CURTIME().

CURRENT_TIMESTAMP and CURRENT_TIMESTAMP()

CURRENT_TIMESTAMP and CURRENT_TIMESTAMP() are synonyms for NOW().

DATE(expr)

Extracts the date part of the date or datetime expression expr.

mysql> SELECT DATE('2003-12-31 01:02:03');
+---------------------------------------------------------+
| DATE('2003-12-31 01:02:03') |
+---------------------------------------------------------+
| 2003-12-31 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DATEDIFF(expr1,expr2)

DATEDIFF() returns expr1 . expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation.

mysql> SELECT DATEDIFF('1997-12-31 23:59:59','1997-12-30');
+---------------------------------------------------------+
| DATEDIFF('1997-12-31 23:59:59','1997-12-30') |
+---------------------------------------------------------+
| 1 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DATE_ADD(date,INTERVAL expr unit), DATE_SUB(date,INTERVAL expr unit)

These functions perform date arithmetic. date is a DATETIME or DATE value specifying the starting date. expr is an expression specifying the interval value to be added or subtracted from the starting date. expr is a string; it may start with a .-. for negative intervals. unit is a keyword indicating the units in which the expression should be interpreted.

The INTERVAL keyword and the unit specifier are not case sensitive.

The following table shows the expected form of the expr argument for each unit value;

unit Value ExpectedexprFormat
MICROSECOND MICROSECONDS
SECOND SECONDS
MINUTE MINUTES
HOUR HOURS
DAY DAYS
WEEK WEEKS
MONTH MONTHS
QUARTER QUARTERS
YEAR YEARS
SECOND_MICROSECOND 'SECONDS.MICROSECONDS'
MINUTE_MICROSECOND 'MINUTES.MICROSECONDS'
MINUTE_SECOND 'MINUTES:SECONDS'
HOUR_MICROSECOND 'HOURS.MICROSECONDS'
HOUR_SECOND 'HOURS:MINUTES:SECONDS'
HOUR_MINUTE 'HOURS:MINUTES'
DAY_MICROSECOND 'DAYS.MICROSECONDS'
DAY_SECOND 'DAYS HOURS:MINUTES:SECONDS'
DAY_MINUTE 'DAYS HOURS:MINUTES'
DAY_HOUR 'DAYS HOURS'
YEAR_MONTH 'YEARS-MONTHS'
The values QUARTER and WEEK are available beginning with MySQL 5.0.0.

mysql> SELECT DATE_ADD('1997-12-31 23:59:59',
-> INTERVAL '1:1' MINUTE_SECOND);
+---------------------------------------------------------+
| DATE_ADD('1997-12-31 23:59:59', INTERVAL... |
+---------------------------------------------------------+
| 1998-01-01 00:01:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT DATE_ADD('1999-01-01', INTERVAL 1 HOUR);
+---------------------------------------------------------+
| DATE_ADD('1999-01-01', INTERVAL 1 HOUR) |
+---------------------------------------------------------+
| 1999-01-01 01:00:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DATE_FORMAT(date,format)

Formats the date value according to the format string.

The following specifiers may be used in the format string. The .%. character is required before format specifier characters.

Specifier Description
%a Abbreviated weekday name (Sun..Sat)
%b Abbreviated month name (Jan..Dec)
%c Month, numeric (0..12)
%D Day of the month with English suffix (0th, 1st, 2nd, 3rd, .)
%d Day of the month, numeric (00..31)
%e Day of the month, numeric (0..31)
%f Microseconds (000000..999999)
%H Hour (00..23)
%h Hour (01..12)
%I Hour (01..12)
%i Minutes, numeric (00..59)
%j Day of year (001..366)
%k Hour (0..23)
%l Hour (1..12)
%M Month name (January..December)
%m Month, numeric (00..12)
%p AM or PM
%r Time, 12-hour (hh:mm:ss followed by AM or PM)
%S Seconds (00..59)
%s Seconds (00..59)
%T Time, 24-hour (hh:mm:ss)
%U Week (00..53), where Sunday is the first day of the week
%u Week (00..53), where Monday is the first day of the week
%V Week (01..53), where Sunday is the first day of the week; used with %X
%v Week (01..53), where Monday is the first day of the week; used with %x
%W Weekday name (Sunday..Saturday)
%w Day of the week (0=Sunday..6=Saturday)
%X Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V
%x Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v
%Y Year, numeric, four digits
%y Year, numeric (two digits)
%% A literal .%. character
%x x, for any.x. not listed above
mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00', '%W %M %Y');
+---------------------------------------------------------+
| DATE_FORMAT('1997-10-04 22:23:00', '%W %M %Y') |
+---------------------------------------------------------+
| Saturday October 1997 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT DATE_FORMAT('1997-10-04 22:23:00'
-> '%H %k %I %r %T %S %w');
+---------------------------------------------------------+
| DATE_FORMAT('1997-10-04 22:23:00....... |
+---------------------------------------------------------+
| 22 22 10 10:23:00 PM 22:23:00 00 6 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DATE_SUB(date,INTERVAL expr unit)

This is similar to DATE_ADD() function.

DAY(date)

DAY() is a synonym for DAYOFMONTH().

DAYNAME(date)

Returns the name of the weekday for date.

mysql> SELECT DAYNAME('1998-02-05');
+---------------------------------------------------------+
| DAYNAME('1998-02-05') |
+---------------------------------------------------------+
| Thursday |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DAYOFMONTH(date)

Returns the day of the month for date, in the range 0 to 31.

mysql> SELECT DAYOFMONTH('1998-02-03');
+---------------------------------------------------------+
| DAYOFMONTH('1998-02-03') |
+---------------------------------------------------------+
| 3 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DAYOFWEEK(date)

Returns the weekday index for date (1 = Sunday, 2 = Monday, ., 7 = Saturday). These index values correspond to the ODBC standard.

mysql> SELECT DAYOFWEEK('1998-02-03');
+---------------------------------------------------------+
|DAYOFWEEK('1998-02-03') |
+---------------------------------------------------------+
| 3 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
DAYOFYEAR(date)

Returns the day of the year for date, in the range 1 to 366.

mysql> SELECT DAYOFYEAR('1998-02-03');
+---------------------------------------------------------+
| DAYOFYEAR('1998-02-03') |
+---------------------------------------------------------+
| 34 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
EXTRACT(unit FROM date)

The EXTRACT() function uses the same kinds of unit specifiers as DATE_ADD() or DATE_SUB(), but extracts parts from the date rather than performing date arithmetic.

mysql> SELECT EXTRACT(YEAR FROM '1999-07-02');
+---------------------------------------------------------+
| EXTRACT(YEAR FROM '1999-07-02') |
+---------------------------------------------------------+
| 1999 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT EXTRACT(YEAR_MONTH FROM '1999-07-02 01:02:03');
+---------------------------------------------------------+
| EXTRACT(YEAR_MONTH FROM '1999-07-02 01:02:03') |
+---------------------------------------------------------+
| 199907 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
FROM_DAYS(N)

Given a day number N, returns a DATE value.

mysql> SELECT FROM_DAYS(729669);
+---------------------------------------------------------+
| FROM_DAYS(729669) |
+---------------------------------------------------------+
| 1997-10-07 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
Use FROM_DAYS() with caution on old dates. It is not intended for use with values that precede the advent of the Gregorian calendar (1582).

FROM_UNIXTIME(unix_timestamp)

FROM_UNIXTIME(unix_timestamp,format)

Returns a representation of the unix_timestamp argument as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone. unix_timestamp is an internal timestamp value such as is produced by the UNIX_TIMESTAMP() function.

If format is given, the result is formatted according to the format string, which is used the same way as listed in the entry for the DATE_FORMAT() function.

mysql> SELECT FROM_UNIXTIME(875996580);
+---------------------------------------------------------+
| FROM_UNIXTIME(875996580) |
+---------------------------------------------------------+
| 1997-10-04 22:23:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
HOUR(time)

Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of TIME values actually is much larger, so HOUR can return values greater than 23.

mysql> SELECT HOUR('10:05:03');
+---------------------------------------------------------+
| HOUR('10:05:03') |
+---------------------------------------------------------+
| 10 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
LAST_DAY(date)

Takes a date or datetime value and returns the corresponding value for the last day of the month. Returns NULL if the argument is invalid.

mysql> SELECT LAST_DAY('2003-02-05');
+---------------------------------------------------------+
| LAST_DAY('2003-02-05') |
+---------------------------------------------------------+
| 2003-02-28 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
LOCALTIME and LOCALTIME()

LOCALTIME and LOCALTIME() are synonyms for NOW().

LOCALTIMESTAMP and LOCALTIMESTAMP()

LOCALTIMESTAMP and LOCALTIMESTAMP() are synonyms for NOW().

MAKEDATE(year,dayofyear)

Returns a date, given year and day-of-year values. dayofyear must be greater than 0 or the result is NULL.

mysql> SELECT MAKEDATE(2001,31), MAKEDATE(2001,32);
+---------------------------------------------------------+
| MAKEDATE(2001,31), MAKEDATE(2001,32) |
+---------------------------------------------------------+
| '2001-01-31', '2001-02-01' |
+---------------------------------------------------------+
1 row in set (0.00 sec)
MAKETIME(hour,minute,second)

Returns a time value calculated from the hour, minute, and second arguments.

mysql> SELECT MAKETIME(12,15,30);
+---------------------------------------------------------+
| MAKETIME(12,15,30) |
+---------------------------------------------------------+
| '12:15:30' |
+---------------------------------------------------------+
1 row in set (0.00 sec)
MICROSECOND(expr)

Returns the microseconds from the time or datetime expression expr as a number in the range from 0 to 999999.

mysql> SELECT MICROSECOND('12:00:00.123456');
+---------------------------------------------------------+
| MICROSECOND('12:00:00.123456') |
+---------------------------------------------------------+
| 123456 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
MINUTE(time)

Returns the minute for time, in the range 0 to 59.

mysql> SELECT MINUTE('98-02-03 10:05:03');
+---------------------------------------------------------+
| MINUTE('98-02-03 10:05:03') |
+---------------------------------------------------------+
| 5 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
MONTH(date)

Returns the month for date, in the range 0 to 12.

mysql> SELECT MONTH('1998-02-03')
+---------------------------------------------------------+
| MONTH('1998-02-03') |
+---------------------------------------------------------+
| 2 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
MONTHNAME(date)

Returns the full name of the month for date.

mysql> SELECT MONTHNAME('1998-02-05');
+---------------------------------------------------------+
| MONTHNAME('1998-02-05') |
+---------------------------------------------------------+
| February |
+---------------------------------------------------------+
1 row in set (0.00 sec)
NOW()

Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone.

mysql> SELECT NOW();
+---------------------------------------------------------+
| NOW() |
+---------------------------------------------------------+
| 1997-12-15 23:50:26 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
PERIOD_ADD(P,N)

Adds N months to period P (in the format YYMM or YYYYMM). Returns a value in the format YYYYMM. Note that the period argument P is not a date value.

mysql> SELECT PERIOD_ADD(9801,2);
+---------------------------------------------------------+
| PERIOD_ADD(9801,2) |
+---------------------------------------------------------+
| 199803 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
PERIOD_DIFF(P1,P2)

Returns the number of months between periods P1 and P2. P1 and P2 should be in the format YYMM or YYYYMM. Note that the period arguments P1 and P2 are not date values.

mysql> SELECT PERIOD_DIFF(9802,199703);
+---------------------------------------------------------+
| PERIOD_DIFF(9802,199703) |
+---------------------------------------------------------+
| 11 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
QUARTER(date)

Returns the quarter of the year for date, in the range 1 to 4.

mysql> SELECT QUARTER('98-04-01');
+---------------------------------------------------------+
| QUARTER('98-04-01') |
+---------------------------------------------------------+
| 2 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
SECOND(time)

Returns the second for time, in the range 0 to 59.

mysql> SELECT SECOND('10:05:03');
+---------------------------------------------------------+
| SECOND('10:05:03') |
+---------------------------------------------------------+
| 3 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
SEC_TO_TIME(seconds)

Returns the seconds argument, converted to hours, minutes, and seconds, as a value in 'HH:MM:SS' or HHMMSS format, depending on whether the function is used in a string or numeric context.

mysql> SELECT SEC_TO_TIME(2378);
+---------------------------------------------------------+
| SEC_TO_TIME(2378) |
+---------------------------------------------------------+
| 00:39:38 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
STR_TO_DATE(str,format)

This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.

mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
+---------------------------------------------------------+
| STR_TO_DATE('04/31/2004', '%m/%d/%Y') |
+---------------------------------------------------------+
| 2004-04-31 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
SUBDATE(date,INTERVAL expr unit) and SUBDATE(expr,days)

When invoked with the INTERVAL form of the second argument, SUBDATE() is a synonym for DATE_SUB(). For information on the INTERVAL unit argument, see the discussion for DATE_ADD().

mysql> SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY);
+---------------------------------------------------------+
| DATE_SUB('1998-01-02', INTERVAL 31 DAY) |
+---------------------------------------------------------+
| 1997-12-02 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT SUBDATE('1998-01-02', INTERVAL 31 DAY);
+---------------------------------------------------------+
| SUBDATE('1998-01-02', INTERVAL 31 DAY) |
+---------------------------------------------------------+
| 1997-12-02 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
SUBTIME(expr1,expr2)

SUBTIME() returns expr1 . expr2 expressed as a value in the same format as expr1. expr1 is a time or datetime expression, and expr2 is a time.

mysql> SELECT SUBTIME('1997-12-31 23:59:59.999999',
-> '1 1:1:1.000002');
+---------------------------------------------------------+
| SUBTIME('1997-12-31 23:59:59.999999'... |
+---------------------------------------------------------+
| 1997-12-30 22:58:58.999997 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
SYSDATE()

Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format, depending on whether the function is used in a string or numeric context.

mysql> SELECT SYSDATE();
+---------------------------------------------------------+
| SYSDATE() |
+---------------------------------------------------------+
| 2006-04-12 13:47:44 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIME(expr)

Extracts the time part of the time or datetime expression expr and returns it as a string.

mysql> SELECT TIME('2003-12-31 01:02:03');
+---------------------------------------------------------+
| TIME('2003-12-31 01:02:03') |
+---------------------------------------------------------+
| 01:02:03 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIMEDIFF(expr1,expr2)

TIMEDIFF() returns expr1 . expr2 expressed as a time value. expr1 and expr2 are time or date-and-time expressions, but both must be of the same type.

mysql> SELECT TIMEDIFF('1997-12-31 23:59:59.000001',
-> '1997-12-30 01:01:01.000002');
+---------------------------------------------------------+
| TIMEDIFF('1997-12-31 23:59:59.000001'..... |
+---------------------------------------------------------+
| 46:58:57.999999 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIMESTAMP(expr), TIMESTAMP(expr1,expr2)

With a single argument, this function returns the date or datetime expression expr as a datetime value. With two arguments, it adds the time expression expr2 to the date or datetime expression expr1 and returns the result as a datetime value.

mysql> SELECT TIMESTAMP('2003-12-31');
+---------------------------------------------------------+
| TIMESTAMP('2003-12-31') |
+---------------------------------------------------------+
| 2003-12-31 00:00:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIMESTAMPADD(unit,interval,datetime_expr)

Adds the integer expression interval to the date or datetime expression datetime_expr. The unit for interval is given by the unit argument, which should be one of the following values: FRAC_SECOND, SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.

The unit value may be specified using one of keywords as shown, or with a prefix of SQL_TSI_. For example, DAY and SQL_TSI_DAY both are legal.

mysql> SELECT TIMESTAMPADD(MINUTE,1,'2003-01-02');
+---------------------------------------------------------+
| TIMESTAMPADD(MINUTE,1,'2003-01-02') |
+---------------------------------------------------------+
| 2003-01-02 00:01:00 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIMESTAMPDIFF(unit,datetime_expr1,datetime_expr2)

Returns the integer difference between the date or datetime expressions datetime_expr1 and datetime_expr2. The unit for the result is given by the unit argument. The legal values for unit are the same as those listed in the description of the TIMESTAMPADD() function.

mysql> SELECT TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01');
+---------------------------------------------------------+
| TIMESTAMPDIFF(MONTH,'2003-02-01','2003-05-01') |
+---------------------------------------------------------+
| 3 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIME_FORMAT(time,format)

This is used like the DATE_FORMAT() function, but the format string may contain format specifiers only for hours, minutes, and seconds.

If the time value contains an hour part that is greater than 23, the %H and %k hour format specifiers produce a value larger than the usual range of 0..23. The other hour format specifiers produce the hour value modulo 12.

mysql> SELECT TIME_FORMAT('100:00:00', '%H %k %h %I %l');
+---------------------------------------------------------+
| TIME_FORMAT('100:00:00', '%H %k %h %I %l') |
+---------------------------------------------------------+
| 100 100 04 04 4 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TIME_TO_SEC(time)

Returns the time argument, converted to seconds.

mysql> SELECT TIME_TO_SEC('22:23:00');
+---------------------------------------------------------+
| TIME_TO_SEC('22:23:00') |
+---------------------------------------------------------+
| 80580 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
TO_DAYS(date)

Given a date date, returns a day number (the number of days since year 0).

mysql> SELECT TO_DAYS(950501);
+---------------------------------------------------------+
| TO_DAYS(950501) |
+---------------------------------------------------------+
| 728779 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
UNIX_TIMESTAMP(), UNIX_TIMESTAMP(date)

If called with no argument, returns a Unix timestamp (seconds since '1970-01-01 00:00:00' UTC) as an unsigned integer. If UNIX_TIMESTAMP() is called with a date argument, it returns the value of the argument as seconds since '1970-01-01 00:00:00' UTC. date may be a DATE string, a DATETIME string, a TIMESTAMP, or a number in the format YYMMDD or YYYYMMDD.

mysql> SELECT UNIX_TIMESTAMP();
+---------------------------------------------------------+
| UNIX_TIMESTAMP() |
+---------------------------------------------------------+
| 882226357 |
+---------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT UNIX_TIMESTAMP('1997-10-04 22:23:00');
+---------------------------------------------------------+
| UNIX_TIMESTAMP('1997-10-04 22:23:00') |
+---------------------------------------------------------+
| 875996580 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
UTC_DATE, UTC_DATE()

Returns the current UTC date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context.

mysql> SELECT UTC_DATE(), UTC_DATE() + 0;
+---------------------------------------------------------+
| UTC_DATE(), UTC_DATE() + 0 |
+---------------------------------------------------------+
| 2003-08-14, 20030814 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
UTC_TIME, UTC_TIME()

Returns the current UTC time as a value in 'HH:MM:SS' or HHMMSS format, depending on whether the function is used in a string or numeric context.

mysql> SELECT UTC_TIME(), UTC_TIME() + 0;
+---------------------------------------------------------+
| UTC_TIME(), UTC_TIME() + 0 |
+---------------------------------------------------------+
| 18:07:53, 180753 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
UTC_TIMESTAMP, UTC_TIMESTAMP()

Returns the current UTC date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS format, depending on whether the function is used in a string or numeric context.

mysql> SELECT UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0;
+---------------------------------------------------------+
| UTC_TIMESTAMP(), UTC_TIMESTAMP() + 0 |
+---------------------------------------------------------+
| 2003-08-14 18:08:04, 20030814180804 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
WEEK(date[,mode])

This function returns the week number for date. The two-argument form of WEEK() allows you to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If the mode argument is omitted, the value of the default_week_format system variable is used

Mode First Day of week Range Week 1 is the first week .
0 Sunday 0-53 with a Sunday in this year
1 Monday 0-53 with more than 3 days this year
2 Sunday 1-53 with a Sunday in this year
3 Monday 1-53 with more than 3 days this year
4 Sunday 0-53 with more than 3 days this year
5 Monday 0-53 with a Monday in this year
6 Sunday 1-53 with more than 3 days this year
7 Monday 1-53 with a Monday in this year
mysql> SELECT WEEK('1998-02-20');
+---------------------------------------------------------+
| WEEK('1998-02-20') |
+---------------------------------------------------------+
| 7 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
WEEKDAY(date)

Returns the weekday index for date (0 = Monday, 1 = Tuesday, . 6 = Sunday).

mysql> SELECT WEEKDAY('1998-02-03 22:23:00');
+---------------------------------------------------------+
| WEEKDAY('1998-02-03 22:23:00') |
+---------------------------------------------------------+
| 1 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
WEEKOFYEAR(date)

Returns the calendar week of the date as a number in the range from 1 to 53. WEEKOFYEAR() is a compatibility function that is equivalent to WEEK(date,3).

mysql> SELECT WEEKOFYEAR('1998-02-20');
+---------------------------------------------------------+
| WEEKOFYEAR('1998-02-20') |
+---------------------------------------------------------+
| 8 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
YEAR(date)

Returns the year for date, in the range 1000 to 9999, or 0 for the .zero. date.

mysql> SELECT YEAR('98-02-03');
+---------------------------------------------------------+
| YEAR('98-02-03') |
+---------------------------------------------------------+
| 1998 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
YEARWEEK(date), YEARWEEK(date,mode)

Returns year and week for a date. The mode argument works exactly like the mode argument to WEEK(). The year in the result may be different from the year in the date argument for the first and the last week of the year.

mysql> SELECT YEARWEEK('1987-01-01');
+---------------------------------------------------------+
| YEAR('98-02-03')YEARWEEK('1987-01-01') |
+---------------------------------------------------------+
| 198653 |
+---------------------------------------------------------+
1 row in set (0.00 sec)
Note that the week number is different from what the WEEK() function would return (0) for optional arguments 0 or 1, as WEEK() then returns the week in the context of the given year.

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144月/15关

mysql 中文字段排序( 按拼音首字母排序) 的查询语句

发布在 邵珠庆

在处理使用Mysql时，数据表采用utf8字符集，使用中发现中文不能直接按照拼音排序

 

如果数据表tbl的某字段name的字符编码是latin1_swedish_ci

select * from `tbl` order by birary(name) asc ;

 

如果数据表tbl的某字段name的字符编码是utf8_general_ci

 

SELECT name FROM `tbl` WHERE 1 ORDER BY CONVERT( name USING gbk ) COLLATE gbk_chinese_ci ASC

 

===================

$orderby="convert(`group` USING gbk) COLLATE gbk_chinese_ci,displayorder,navid"

标签: , , , , , , , 没有评论
1211月/14关

php/mysql/jquery实现各系统流行的瀑布流显示方式，实现很简单的！！！！

发布在 邵珠庆

大家在用这个东西的时候一定要计得有这么几个文件，一个是jquery.js 还有就是你自己数据库的密码。和相对应的图片才可以正常看到效果。下面就是这里所有的代码！！！

HTML文件：waterfall.html

1. [代码][PHP]代码     

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View Code
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>瀑布流-Derek</title>
 <script type="text/javascript" language="javascript" src="jquery.js"></script>
 <link type="text/css" rel="stylesheet" href="waterfall.css" />
 <script type="text/javascript" language="javascript" src="waterfall.js"></script>
 </head>
 <body>
  
     <ul id="stage">
         <li></li>
         <li></li>
         <li></li>
         <li></li>
     </ul>
  
 </body>
 </html>
/*
 *  Javascript文件：waterfall.js
 */
$(function(){
     jsonajax();
 });
  
 //这里就要进行计算滚动条当前所在的位置了。如果滚动条离最底部还有100px的时候就要进行调用ajax加载数据
 $(window).scroll(function(){   
     //此方法是在滚动条滚动时发生的函数
     // 当滚动到最底部以上100像素时，加载新内容
     var $doc_height,$s_top,$now_height;
     $doc_height = $(document).height();        //这里是document的整个高度
     $s_top = $(this).scrollTop();            //当前滚动条离最顶上多少高度
     $now_height = $(this).height();            //这里的this 也是就是window对象
     if(($doc_height - $s_top - $now_height) < 100) jsonajax();   
 });
  
  
 //做一个ajax方法来请求data.php不断的获取数据
 var $num = 0;
 function jsonajax(){
      
     $.ajax({
         url:'data.php',
         type:'POST',
         data:"num="+$num++,
         dataType:'json',
         success:function(json){
             if(typeof json == 'object'){
                 var neirou,$row,iheight,temp_h;
                 for(var i=0,l=json.length;i<l;i++){
                     neirou = json[i];    //当前层数据
                     //找了高度最少的列做添加新内容
                     iheight  =  -1;
                     $("#stage li").each(function(){
                         //得到当前li的高度
                         temp_h = Number($(this).height());
                         if(iheight == -1 || iheight >temp_h){
                             iheight = temp_h;
                             $row = $(this); //此时$row是li对象了
                         }
                     });
                     $item = $('<div><img src="'+neirou.img+'" border="0" ><br/>'+neirou.title+'</div>').hide();
                     $row.append($item);
                     $item.fadeIn();
                 }
             }
         }
     });
 }
 
/*
 *  CSS文件：waterfall.css
 */
 
body{text-align:center;}
/*Download by http://www.codefans.net*/
#stage{ margin:0 auto; padding:0; width:880px; }
#stage li{ margin:0; padding:0; list-style:none;float:left; width:220px;}
#stage li div{ font-size:12px; padding:10px; color:#999999; text-align:left; }
 
 
/*
 *  php文件：data.php
 */
<?php
 $link = mysql_connect("localhost","root","");
 $sql = "use waterfall";
 mysql_query($sql,$link);
 $sql = "set names utf8";
 mysql_query($sql,$link);
 $num = $_POST['num'] *10;
 if($_POST['num'] != 0) $num +1;
 $sql = "select img,title from content limit ".$num.",10";
 $result = mysql_query($sql,$link);
 $temp_arr = array();
 while($row = mysql_fetch_assoc($result)){
     $temp_arr[] = $row;
 }
 $json_arr = array();
 foreach($temp_arr as $k=>$v){
     $json_arr[]  = (object)$v;
 }
 //print_r($json_arr);
 echo json_encode( $json_arr );

2. [文件] waterfall.zip ~ 8KB     下载(850)     

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710月/14关

linux下mysql的root密码忘记解决方法

发布在 邵珠庆

1．首先确认服务器出于安全的状态，也就是没有人能够任意地连接MySQL数据库。 
因为在重新设置MySQL的root密码的期间，MySQL数据库完全出于没有密码保护的 
状态下，其他的用户也可以任意地登录和修改MySQL的信息。可以采用将MySQL对 
外的端口封闭，并且停止Apache以及所有的用户进程的方法实现服务器的准安全 
状态。最安全的状态是到服务器的Console上面操作，并且拔掉网线。 
2．修改MySQL的登录设置： 
# vi /etc/my.cnf 
在[mysqld]的段中加上一句：skip-grant-tables 
例如： 
[mysqld] 
datadir=/var/lib/mysql 
socket=/var/lib/mysql/mysql.sock 
skip-grant-tables 
保存并且退出vi。 
3．重新启动mysqld 
# /etc/init.d/mysqld restart 
Stopping MySQL: [ OK ] 
Starting MySQL: [ OK ] 
4．登录并修改MySQL的root密码 
# /usr/bin/mysql 
Welcome to the MySQL monitor. Commands end with ; or g. 
Your MySQL connection id is 3 to server version: 3.23.56 
Type 'help;' or 'h' for help. Type 'c' to clear the buffer. 
mysql> USE mysql ; 
Reading table information for completion of table and column names 
You can turn off this feature to get a quicker startup with -A 
Database changed 
mysql> UPDATE user SET Password = password ( 'new-password' ) WHERE User = 'root' ; 
Query OK, 0 rows affected (0.00 sec) 
Rows matched: 2 Changed: 0 Warnings: 0 
mysql> flush privileges ; 
Query OK, 0 rows affected (0.01 sec) 
mysql> quit 
Bye 
5．将MySQL的登录设置修改回来 
# vi /etc/my.cnf 
将刚才在[mysqld]的段中加上的skip-grant-tables删除 
保存并且退出vi。 
6．重新启动mysqld 
# /etc/init.d/mysqld restart 
Stopping MySQL: [ OK ] 
Starting MySQL: [ OK ]

Work for fun,Live for love!
MySQL远程连接ERROR 2003 (HY000):Can't connect to MySQL server on'XXXXX'(111) 的问题
1.查看配置文件:
skip-networking #注释掉 因为它是屏蔽掉一切TCP/IP连接
bind-address = 127.0.0.1 #它和上一个选项是异曲同工，要想远程连接，也得注释掉
2.如果以上工作都做过还是出现：
ERROR 2003 (HY000): Can't connect to MySQL server on '*.*.*.*' (113)，那就得考虑防火墙的问题了，关掉防火墙/etc/rc.d/init.d/iptables stop
修改完后需要 restart mysql (/etc/init.d/mysql restart) 

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1612月/13关

Mysql函数GROUP_CONCAT

发布在 邵珠庆

GROUP_CONCAT()是MySQL数据库提供的一个函数，通常跟GROUP BY一起用,具体可参考MySQL官方文挡:http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat。

语法:

GROUP_CONCAT([DISTINCT] expr [,expr ...] [ORDER BY {unsigned_integer | col_name | expr} [ASC |DESC] [,col_name ...]] [SEPARATOR str_val])

1.例如:
SELECT student_id, GROUP_CONCAT(courses_id) AS courses FROM student_courses WHEREstudent_id=2 GROUP BY student_id; 
+------------+---------+ 
| student_id | courses | 
+------------+---------+ 
| 2          | 3,4,5 |
+------------+---------+ 
这 就不需要用php循环了
$row = $pdo->query("SELECT student_id, GROUP_CONCAT(courses_id) AS courses FROM student_courses WHERE student_id=2 GROUP BY student_id");
$result = explode(',', $row['courses']); 

2.当然分隔符还可以自定义，默认是以“,”作为分隔符，若要改为“|||”，则使用SEPARATOR来指定，例如：

SELECT student_id, GROUP_CONCAT(courses_id SEPARATOR '|||') AS courses FROM student_coursesWHERE student_id=2 GROUP BY student_id;
+------------+---------+ 
| student_id | courses | 
+------------+---------+ 
| 2          | 3|||4|||5 |
+------------+---------+ 

3.除此之外，还可以对这个组的值来进行排序再连接成字符串，例如按courses_id降序来排：
SELECT student_id, GROUP_CONCAT(courses_id ORDER BY courses_id DESC) AS courses FROMstudent_courses WHERE student_id=2 GROUP BY student_id;
+------------+---------+ 
| student_id | courses | 
+------------+---------+ 
| 2 | 5,4,3 |
+------------+---------+ 

4.需要注意的：

a.int字段的连接陷阱

当你用group_concat的时候请注意，连接起来的字段如果是int型，一定要转换成char再拼起来，
否则在你执行后(ExecuteScalar或者其它任何执行SQL返回结果的方法)返回的将不是一个逗号隔开的串，
而是byte[]。

该问题当你在SQLyog等一些工具中是体现不出来的，所以很难发现。

select group_concat(ipaddress) from t_ip 返回逗号隔开的串
select group_concat(id) from t_ip 返回byte[]
select group_concat(CAST(id as char)) from t_dep 返回逗号隔开的串
select group_concat(Convert(id , char)) from t_dep 返回逗号隔开的串

附Cast,convert的用法：
CAST(expr AS type), CONVERT(expr,type) , CONVERT(expr USING transcoding_name)
CAST() 和CONVERT() 函数可用来获取一个类型的值，并产生另一个类型的值。

这个类型 可以是以下值其中的 一个：

BINARY[(N)]
CHAR[(N)]
DATE
DATETIME
DECIMAL
SIGNED [INTEGER]
TIME
UNSIGNED [INTEGER]

b.长度陷阱
用了group_concat后，select里如果使用了limit是不起作用的.
用group_concat连接字段的时候是有长度限制的，并不是有多少连多少。但你可以设置一下。

使用group_concat_max_len系统变量，你可以设置允许的最大长度。
程序中进行这项操作的语法如下，其中 val 是一个无符号整数：
SET [SESSION | GLOBAL] group_concat_max_len = val;
若已经设置了最大长度， 则结果被截至这个最大长度。

在SQLyog中执行 SET GLOBAL group_concat_max_len = 10 后，重新打开SQLyog，设置就会生效。

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612月/13关

mysql中or和in的效率问题

发布在 邵珠庆

在网上一直看到的是or和in的效率没啥区别，一直也感觉是这样，前几天刚好在看《mysql数据库开发的36条军规》的文章，里面提到了or和in的效率问题，文中提到or的效率为O(n)，而in的效率为O(logn), 当n越大的时候效率相差越明显。今天刚好有时间决定对心中的疑惑进行测试，下面是详细的测试过程。

第一步，创建测试表，并生成测试数据，测试数据为1000万条记录。数据库版本为5.1.63。数据库中关闭了query cache，因此数据库缓存不会对查询造成影响。具体的代码如下：

点击(此处)折叠或打开

  1. #创建测试的test表
  2. DROP TABLE IF EXISTS test; 
  3. CREATE TABLE test( 
  4.     ID INT(10) NOT NULL, 
  5.     `Name` VARCHAR(20) DEFAULT '' NOT NULL, 
  6.     PRIMARY KEY( ID ) 
  7. )ENGINE=INNODB DEFAULT CHARSET utf8; 
  8. #创建生成测试数据的存储过程
  9. DROP PROCEDURE IF EXISTS pre_test; 
  10. DELIMITER //
  11. CREATE PROCEDURE pre_test() 
  12. BEGIN 
  13. DECLARE i INT DEFAULT 0; 
  14. SET autocommit = 0; 
  15. WHILE i<10000000 DO 
  16. INSERT INTO test ( ID,`Name` ) VALUES( i, CONCAT( 'Carl', i ) ); 
  17. SET i = i+1; 
  18. IF i%2000 = 0 THEN 
  19. COMMIT; 
  20. END IF; 
  21. END WHILE; 
  22. END; //
  23. DELIMITER ;
  24. #执行存储过程生成测试数据
  25. CALL pre_test();


第二步：分三中情况进行测试，分别是：
第一种情况：in和or所在列为主键的情形。
第二种情况：in和or所在列创建有索引的情形。
第二种情况：in和or所在列没有索引的情形。
每种情况又采用不同的in和or的数量进行测试。由于测试语句的数据量有4种情况，我这里就称为A组、B组、C组、D组,其中A组为3个值，B组为150个值，C组为300个值，D组为1000个值。具体的测试语句如下：

点击(此处)折叠或打开

  1. #A组
  2. #in和or中有3条数据的情况
  3. SELECT * FROM test WHERE id IN (1,23,48);
  4. SELECT * FROM test WHERE id =1 OR id=23 OR id=48;
  5. #B组
  6. #in和or中有150条数据的情况
  7. SELECT * FROM test WHERE id IN (59617932,98114476,89047409,26968186,56586105,35488201,53251989,18182139,71164231,57655852,7948544,60658339,50758185,66667117,34771253,68699137,27877290,44275282,1585444,71219424,90937482,83928635,24588528,81933207,9607562,12013895,84640278,85549596,53249244,8567444,85402877,15040223,54266509,17718135,91687882,22930500,94756430,66031097,13084573,18137443,89917778,46845456,43939093,35943480,18213703,46362815,49835919,83137546,2101409,74932951,11984477,93113331,77848222,68546065,33728734,90793684,44975642,61387237,52483391,97716233,49449060,22411182,30776331,60597240,6911731,45789095,62075344,8379933,97910423,86861971,81342386,93423963,83852896,18566482,22747687,51420625,75862064,26402882,93958561,85202979,97049369,67674725,9475653,92302381,78133617,49295001,36517340,81387142,15707241,60832834,93157830,64171432,58537826,70141767,7326025,36632075,9639624,8900056,99702164,35108945,87820933,57302965,16652391,41845132,62184393,70136913,79574630,32562398,94616790,61258220,73162018,81644480,19453596,97380163,1204733,33357040,84854495,13888863,49041868,89272326,38405345,571248,6349029,70755321,79307694,60619684,92624181,73135306,23279848,95612954,55845916,6223606,43836918,37459781,67969314,99398872,7616960,37189193,50151920,62881879,12364637,33204320,27135672,28441504,47373461,87967926,30631796,20053540,18735984,83406724);
  8. SELECT * FROM test WHERE id=59617932 OR id=98114476 OR id=89047409 OR id=26968186 OR id=56586105 OR id=35488201 OR id=53251989 OR id=18182139 OR id=71164231 OR id=57655852 OR id=7948544 OR id=60658339 OR id=50758185 OR id=66667117 OR id=34771253 OR id=68699137 OR id=27877290 ORid=44275282 OR id=1585444 OR id=71219424 OR id=90937482 OR id=83928635 OR id=24588528 OR id=81933207 OR id=9607562 OR id=12013895 OR id=84640278 OR id=85549596 OR id=53249244 OR id=8567444 OR id=85402877 OR id=15040223 OR id=54266509 OR id=17718135 OR id=91687882 OR id=22930500OR id=94756430 OR id=66031097 OR id=13084573 OR id=18137443 OR id=89917778 OR id=46845456 OR id=43939093 OR id=35943480 OR id=18213703 OR id=46362815 OR id=49835919 OR id=83137546 OR id=2101409 OR id=74932951 OR id=11984477 OR id=93113331 OR id=77848222 OR id=68546065 OR id=33728734 OR id=90793684 OR id=44975642 OR id=61387237 OR id=52483391 OR id=97716233 OR id=49449060 OR id=22411182 OR id=30776331 OR id=60597240 OR id=6911731 OR id=45789095 OR id=62075344 OR id=8379933 OR id=97910423 OR id=86861971 OR id=81342386 OR id=93423963 OR id=83852896 OR id=18566482 OR id=22747687 OR id=51420625 OR id=75862064 OR id=26402882 OR id=93958561 OR id=85202979 OR id=97049369 OR id=67674725 OR id=9475653 OR id=92302381 OR id=78133617 OR id=49295001 OR id=36517340 OR id=81387142 OR id=15707241 OR id=60832834 OR id=93157830 OR id=64171432 OR id=58537826 OR id=70141767 OR id=7326025 OR id=36632075 OR id=9639624 OR id=8900056 OR id=99702164 OR id=35108945 OR id=87820933 OR id=57302965 OR id=16652391 OR id=41845132 OR id=62184393 OR id=70136913 OR id=79574630 OR id=32562398 OR id=94616790 OR id=61258220 OR id=73162018 OR id=81644480 OR id=19453596 OR id=97380163 OR id=1204733 OR id=33357040 OR id=84854495 OR id=13888863 OR id=49041868 OR id=89272326OR id=38405345 OR id=571248 OR id=6349029 OR id=70755321 OR id=79307694 OR id=60619684 OR id=92624181 OR id=73135306 OR id=23279848 OR id=95612954 OR id=55845916 OR id=6223606 OR id=43836918 OR id=37459781 OR id=67969314 OR id=99398872 OR id=7616960 OR id=37189193 OR id=50151920 OR id=62881879 OR id=12364637 OR id=33204320 OR id=27135672 OR id=28441504 OR id=47373461 OR id=87967926 OR id=30631796 OR id=20053540 ORid=18735984 OR id=83406724;
  9. #C组
  10. #in和or中有300条数据的情况
  11. SELECT * FROM test WHERE id IN (37092877,94859722,74276090,8763830,38727241,95732954,93414819,55070016,3591352,73857925,92290525,15210159,83905516,54934589,83004136,31442143,6060569,22209206,27649629,11464943,77822402,28714780,10058522,62252663,13751461,38997875,47320577,64507359,36137908,54297630,97411161,56542672,22017966,55190708,70072386,24300664,93413617,23621629,74772508,62774612,43001947,46161388,85563006,70177147,63960440,18001207,81734850,10635060,6551152,54877885,44426798,73950635,18713144,21690065,82153543,26048520,79954773,22411093,97307339,74193176,1413532,88006544,36062746,24043946,17132007,95958217,26112542,27303972,17247403,56778979,60928031,69369613,90584759,86234538,41726089,25315005,27568726,25091624,15307765,83130887,42726438,75872353,18991223,47819224,75457713,54659391,54889687,65229322,17124556,38376043,1989975,45973571,48597804,58632319,43388664,97010450,94745635,13217373,40472912,40220510,58319808,48228318,48936085,86281500,65466706,96815281,11751559,50188155,76649755,35315411,20360954,17739218,10918461,51429591,41447650,65170472,26810295,80912347,17157209,75851858,61150903,4408208,61200404,6655467,66863737,51549112,61951371,14368308,14663119,8762531,31765056,30560647,41048147,95526521,94929131,56881239,79014587,62705983,15892901,66151473,98846144,79336731,35949035,26250054,97536202,40575682,6965144,91059908,97939380,30854180,1965937,17193347,76584991,70467475,6559872,97386594,13939914,20379091,84906436,45989448,17337270,4949675,96963499,12561575,77153018,73213368,68283041,33977574,86290771,70381017,73095085,454900,44614195,48171334,49603342,7430998,29447060,47643508,82393912,83169846,94256496,35275444,40024984,25377535,46571333,32510994,70927802,92017916,97302502,22859741,32726786,79071601,93977472,47409421,49311618,77366144,84838598,59401507,67110877,42075938,76962007,27984930,72982484,81363683,75017478,88624177,67220235,88290070,26311443,87681081,77960250,4996033,68448074,67762279,99650583,36766422,27233152,71436659,25428777,81481679,51070397,88351803,78755075,26783938,83610840,45650662,86305644,1717314,66176062,6507047,45084786,74402982,55661367,35721238,40424913,24294239,30223531,55367671,56777532,12604154,4870493,14750488,74039611,42549918,70710424,56247316,63002053,71117605,16510883,67417211,34057637,74185092,58603491,66987830,73584171,9178319,47096502,1554825,37756804,85168245,92690138,6120773,99586029,74696745,61803307,56631845,42681796,58965644,68703695,69660559,15879062,26713059,85186928,63117471,53007808,74576547,32187857,13701205,88645881,24507258,87453800,39624977,75862710,62419627,70804059,10461373,18265782,56366177,68093007,75760763,43931574,65808002,49148775,98019987,71183123,53762434,78851856,37767085,89124453,47566746);
  12. SELECT * FROM test WHERE id=37092877 OR id=94859722 OR id=74276090 OR id=8763830 OR id=38727241 OR id=95732954 OR id=93414819 OR id=55070016 OR id=3591352 OR id=73857925 OR id=92290525 OR id=15210159 OR id=83905516 OR id=54934589 OR id=83004136 OR id=31442143 OR id=6060569 OR id=22209206 OR id=27649629 OR id=11464943 OR id=77822402 OR id=28714780 OR id=10058522 OR id=62252663 OR id=13751461 OR id=38997875 OR id=47320577 OR id=64507359 OR id=36137908 OR id=54297630 OR id=97411161 OR id=56542672 OR id=22017966 OR id=55190708 OR id=70072386 OR id=24300664 OR id=93413617 OR id=23621629 OR id=74772508 OR id=62774612 OR id=43001947 OR id=46161388 OR id=85563006 OR id=70177147 OR id=63960440 OR id=18001207 OR id=81734850 OR id=10635060 OR id=6551152 OR id=54877885 OR id=44426798 OR id=73950635 OR id=18713144 OR id=21690065 OR id=82153543 OR id=26048520 OR id=79954773 OR id=22411093 OR id=97307339 OR id=74193176 OR id=1413532 OR id=88006544 OR id=36062746 OR id=24043946 OR id=17132007 OR id=95958217 OR id=26112542 OR id=27303972 OR id=17247403 OR id=56778979 OR id=60928031 OR id=69369613 OR id=90584759 OR id=86234538 OR id=41726089 OR id=25315005 OR id=27568726 OR id=25091624 OR id=15307765 OR id=83130887 OR id=42726438 OR id=75872353 OR id=18991223 OR id=47819224 OR id=75457713 OR id=54659391 OR id=54889687 OR id=65229322 OR id=17124556 OR id=38376043 OR id=1989975 OR id=45973571 OR id=48597804 OR id=58632319 OR id=43388664 OR id=97010450 OR id=94745635 OR id=13217373 OR id=40472912 OR id=40220510 OR id=58319808 OR id=48228318 OR id=48936085 OR id=86281500 OR id=65466706 OR id=96815281 OR id=11751559 OR id=50188155 OR id=76649755 OR id=35315411 ORid=20360954 OR id=17739218 OR id=10918461 OR id=51429591 OR id=41447650 OR id=65170472 OR id=26810295 OR id=80912347 OR id=17157209 OR id=75851858 OR id=61150903 OR id=4408208 OR id=61200404 OR id=6655467 OR id=66863737 OR id=51549112 OR id=61951371 OR id=14368308 OR id=14663119 OR id=8762531 OR id=31765056 OR id=30560647 OR id=41048147 OR id=95526521 OR id=94929131 OR id=56881239 OR id=79014587 OR id=62705983 OR id=15892901 OR id=66151473 OR id=98846144 OR id=79336731 OR id=35949035 OR id=26250054 OR id=97536202 OR id=40575682 OR id=6965144 OR id=91059908 OR id=97939380 OR id=30854180 OR id=1965937 OR id=17193347 OR id=76584991 OR id=70467475 OR id=6559872 OR id=97386594 OR id=13939914OR id=20379091 OR id=84906436 OR id=45989448 OR id=17337270 OR id=4949675 OR id=96963499 OR id=12561575 OR id=77153018 OR id=73213368 OR id=68283041 OR id=33977574 OR id=86290771 OR id=70381017 OR id=73095085 OR id=454900 OR id=44614195 OR id=48171334 OR id=49603342 OR id=7430998 OR id=29447060 OR id=47643508 OR id=82393912 OR id=83169846 OR id=94256496 OR id=35275444 OR id=40024984 OR id=25377535 OR id=46571333 OR id=32510994 OR id=70927802 OR id=92017916 OR id=97302502 OR id=22859741 OR id=32726786 OR id=79071601 OR id=93977472 OR id=47409421 OR id=49311618 OR id=77366144 OR id=84838598 OR id=59401507 OR id=67110877 OR id=42075938 OR id=76962007 OR id=27984930 OR id=72982484 OR id=81363683 OR id=75017478 OR id=88624177 OR id=67220235 OR id=88290070 OR id=26311443 OR id=87681081 OR id=77960250 OR id=4996033 OR id=68448074OR id=67762279 OR id=99650583 OR id=36766422 OR id=27233152 OR id=71436659 OR id=25428777 OR id=81481679 OR id=51070397 OR id=88351803 OR id=78755075 OR id=26783938 OR id=83610840 OR id=45650662 OR id=86305644 OR id=1717314 OR id=66176062 OR id=6507047 OR id=45084786 OR id=74402982 OR id=55661367 OR id=35721238 OR id=40424913 OR id=24294239 OR id=30223531 OR id=55367671 OR id=56777532 OR id=12604154 OR id=4870493 OR id=14750488 OR id=74039611 OR id=42549918 OR id=70710424 OR id=56247316 OR id=63002053 OR id=71117605 OR id=16510883 OR id=67417211 OR id=34057637 OR id=74185092 OR id=58603491 OR id=66987830 OR id=73584171 OR id=9178319 OR id=47096502 OR id=1554825 OR id=37756804 OR id=85168245 OR id=92690138 OR id=6120773 OR id=99586029 OR id=74696745 OR id=61803307 OR id=56631845 OR id=42681796 OR id=58965644 OR id=68703695 OR id=69660559 OR id=15879062 OR id=26713059 OR id=85186928 OR id=63117471 OR id=53007808 OR id=74576547 OR id=32187857 OR id=13701205 OR id=88645881 OR id=24507258 OR id=87453800 OR id=39624977 OR id=75862710 OR id=62419627 OR id=70804059 OR id=10461373 OR id=18265782 OR id=56366177 OR id=68093007 OR id=75760763 OR id=43931574 OR id=65808002 OR id=49148775 OR id=98019987 OR id=71183123 OR id=53762434 OR id=78851856 OR id=37767085 OR id=89124453 OR id=47566746;
  13. #D组
  14. #in和or中有1000条数据的情况
  15. SELECT * FROM test WHERE id IN (93674701,9720356,31732184,53855095,33144472,71864888,27541768,27238726,83648428,12942332,26918445,19781953,81861032,74800064,12286132,6624397,64942581,70512799,46356598,88292448,87069909,38175756,98121997,62570414,15900806,51527968,89092372,8084203,53772848,78871524,3608561,85909562,41702172,61800503,57877634,93407278,30824340,13159046,49055339,73058078,983603,73571456,51694978,75136628,82716874,83551181,7964224,47505945,92695321,15885152,79282709,18572099,27392970,14552787,19848227,4518183,11773920,22285326,71605145,2402625,63365854,70973600,10584706,83688869,84268419,6026005,36545233,24462648,19293921,17561083,52105483,59243514,35230465,34650779,30053489,24225251,59642405,81933853,94495716,26364324,25980634,5579237,14569289,89417845,71178959,4143920,20467990,53316808,21288525,82249537,37737589,44712689,36788133,15668654,4697556,63785060,11555169,36401204,92276179,4135929,75453019,28231031,8649240,11576980,20262028,56242424,11305608,5655216,90240601,28569373,5296027,10739594,72751648,22531251,12535926,36347415,19740655,69125465,7523885,88128548,88830806,25010302,29411467,99614288,32646290,16592563,69036910,32604729,88737786,90169676,57646877,72105460,40027541,70362483,37221415,25284914,69691185,17972978,1544661,47324366,25337670,91133621,63697117,48652228,18538437,79966496,26066529,65334307,8305141,86289387,20178085,88836090,74948034,14101728,7837868,83548120,65602502,83129211,24785681,65000269,49140174,62636621,31096695,52276400,28546681,83631937,57100225,42531528,28326396,38641032,93055463,20525612,66073509,35154065,29007664,12600294,76829494,73917074,67226149,12478806,39842542,70312958,82792046,49668650,46280815,96555182,22966062,83158116,87566530,66277804,7944142,90649884,64342810,9881875,14833854,82959569,50523207,48788762,3801076,14677723,63080506,96215352,36302231,35067168,11695282,19447382,66401373,40822285,41406321,48630216,78955925,57194625,52097877,16169037,44834346,2593695,29948466,41842778,50510473,39669493,64590865,26160800,94882286,2703212,41243905,89363549,82819429,25565895,86836890,58385785,55898457,99305620,43332680,98223672,4494624,25408421,28054121,48197701,90633404,25825550,90631154,24867226,61846156,38911183,67826056,10676975,57116645,474292,82387517,56211477,46555785,49282428,99468990,81172472,26720330,38692582,96073680,88412290,28829489,1816508,75321051,81650509,23175973,42008725,60743468,52532114,731909,77811415,86804961,29675484,33584929,180367,93687804,41093066,5987495,27291494,78229979,63194139,34357776,9992084,22643334,22407822,69740170,29581361,50036776,88768091,82537322,83709895,55361776,90616169,44595355,9468440,54552233,73496954,46104486,92947715,38522993,88515232,57725249,48507967,25309486,91597013,85635814,69579638,68775627,57556546,77900275,95965693,9601780,5448068,54075952,64335883,80114875,14793294,21016639,1959922,93176996,7893733,51407895,45849129,33857790,30096194,78021982,66555961,15842998,77678123,56648395,8171848,80152264,78616680,80098122,22882409,77242219,3124519,60865422,43164198,43256621,73261157,12541949,49780175,23167183,10509251,41809106,25655902,6752559,39850293,50992519,40061483,84526968,93056718,53267125,53914467,39404926,83672449,21484465,34147538,13437853,74079093,50400032,85705998,7557614,10300505,79264856,65669946,23899714,53506926,36081544,11113765,65755643,5826515,60392667,55562374,98132987,80904530,92663352,7283593,3709276,52078745,84847057,34235334,63889320,70036669,58603533,27394053,54766781,50920854,80202681,67618417,82912294,20150728,20042189,86403320,38738266,58393070,50887299,12170654,16212895,37361223,13677457,19503506,20213757,84240441,39618969,26401150,47937678,55871130,79189571,5717133,12444503,95283334,14827147,22008485,56345882,43237192,56980197,68699371,46407250,72120555,70694039,46438829,17774982,36484024,138767,89563532,54847019,7815592,44909604,50479084,17462504,96594465,58317102,92426225,91894699,4501659,43315607,9442814,19705166,87751308,95588126,92372510,20281564,19251355,10321183,34573093,19074704,84678191,24383998,27670253,50223562,34091936,99304371,32477827,54273037,86525073,73253547,33316827,6724062,76707318,78171148,44729510,16697684,68966388,57448392,51380186,35344477,98153122,51825492,27202774,26901641,37527637,88241695,15100257,30418000,21821200,95511035,9289513,83870196,54628801,39402988,88345504,84232433,13925255,70816934,6822742,14400466,430652,87397095,89773413,10883914,89939310,39597573,49356789,62857680,93292662,55644642,81922551,94304087,63705961,137763,22392805,65195561,39498904,22576234,59467794,46389072,66341462,44602153,18204976,45366397,3880945,98231882,27999162,38209350,10599910,77139550,35114264,57109708,93064441,34801782,24938667,84955486,53018874,37969943,64372852,69596670,21288762,12774121,97588451,23575359,10954061,50363988,56263940,61520763,85096643,36250068,19807406,20984386,24520668,44631794,62587890,44963362,7663521,78505677,98442373,90280978,14494324,16069861,11397153,87726305,26133866,42024935,93393929,72575268,76384597,42272046,81658814,40811718,86054463,35997739,51075676,62839927,68179261,19292480,10464999,6342696,75842285,28671096,30029838,19617648,94667632,75855376,83477767,456684,81197213,1961395,79590898,470693,64786459,90138714,30486571,75566704,64467558,21380112,17742907,7733647,92017,64615799,72272722,66873854,77198963,35594848,42694993,12431322,2247181,11020746,42416726,19127785,95444937,36842133,4203521,48149533,45322440,59710953,38250773,31370132,26889920,45927952,55298246,31197238,44744953,35531670,38850041,29759177,76433451,33696500,2823716,68574340,68889919,35744793,64772909,41562277,72606631,54617176,76086087,61060196,1593669,4666059,44201567,97015910,51039786,47534369,36899420,95163693,34278055,24361819,93200909,29991418,63172824,53644148,61454424,44726508,64910883,31088636,14005026,83267869,28497493,12406441,34686539,70646963,7687253,23115957,64556990,49701688,76843379,22370877,11199132,15492661,72101877,47154152,54969058,96696025,33567129,95788960,13301506,38695877,52992551,37817234,82136809,28111091,84977065,93404791,56350318,27576451,84170153,37381626,22432144,35119973,23922989,98961080,14336913,49612713,47410677,41559348,64216475,75502736,16203656,81726720,64541981,82181762,95869963,1086041,76856852,99484886,47292021,99746735,79082859,67416188,46391963,58631281,80994168,9464550,5851058,16534935,63307701,91875109,18716507,15870646,6003995,836024,35610568,39574140,76244639,83403189,51252728,6516065,94907007,81605606,40398075,40258386,6692981,50852074,2869416,97682971,44427361,9608914,58464559,81806036,20047387,66264452,58063775,54179837,48463792,17877188,31718426,64192249,35574859,3671766,88905164,78137697,46929619,21063327,83078770,93293821,41618319,3832324,91310612,79854291,68734227,8826717,80881657,95208907,7079422,30037415,5494004,44809486,97620027,35689182,13120783,26108678,1537176,16538727,50841024,36515680,82635278,11112660,16276555,72997511,93487848,88201238,53997085,15198916,61214583,78412499,3585265,1402827,56445518,47661453,25615629,58263458,62155263,46608555,15822703,82285214,76021596,84571697,45999350,40074628,8219220,5429523,74024203,22354037,17605466,60436920,52777032,65801717,43656316,10424270,48035786,29493228,83897372,62101275,84793857,56894828,70636689,72497148,67388694,68146510,64298548,97117498,25553211,54226533,90395845,24172623,91712292,98280822,54042497,25032894,6833135,39011254,9837753,63507766,26747954,45941264,99955245,80051546,78510759,71322333,92407609,95809491,18999217,23430377,11861293,42583098,24163209,11358738,3237302,3176665,87151132,2789150,63905882,59864282,3673596,19570439,22883042,72375525,51614404,47526636,98443133,99140135,33855918,28333489,81416033,2670097,4897577,24439616,36643479,40817600,76022791,40072872,95193435,96967607,24983145,49883271,94602753,83555050,85455145,34563229,72328311,12002151,71481181,72998351,1489188,38426973,91893116,61594591,89693630,6268166,20056665,62169880,17143472,35103925,22452590,54272289,34236829,78028543,84474414,40386926,50550952,49413559,48781941,22927237,44447815,29960478,47578119,10192558,87733936,88699383,38808712,79944807,84014713,31865463,72617685,19557568,47865990,39069638,20086122,1777562,29018078,78358083,94561719,46281152,99789008,86929490,16534451,55989144,52455669,54561585,97379646,20416183,87617750,76115505,3282482,8383619,45456319,29576432,67750627,61736333,33745442,51502165,35349384,78106651,23232822,94851387,78254073,82406754,10317954,70125940,45067526,27061875,25640164,52574899,93819227,93789607,96122951,31673246,70431904,54067896,37146857,37817889,14058940,60710246,64844350,91604383,71972005,13888349,19093493,27397281,61085409,66529387,82761299,72236310,19277077,96599501,68304096,48292937,97503321,88011133,29224803,79782945,79965966,83716914,90432214,48938902,12498489,30246261,91624049,68652396,23677785,44084687,3865123,37823170,45287730,38784682,28058351,68226368,61569897,44737876,70575908,25568463,24668386,88650569,35559584,1897737,77844785,29780669,84004602,29029776,91003545,48058106,9463847);
  16. SELECT * FROM test WHERE id=93674701 OR id=9720356 OR id=31732184 OR id=53855095 OR id=33144472 OR id=71864888 OR id=27541768 OR id=27238726 OR id=83648428 OR id=12942332 OR id=26918445 OR id=19781953 OR id=81861032 OR id=74800064 OR id=12286132 OR id=6624397 OR id=64942581 OR id=70512799 OR id=46356598 OR id=88292448 OR id=87069909 OR id=38175756 OR id=98121997 OR id=62570414 OR id=15900806 OR id=51527968 OR id=89092372 OR id=8084203 OR id=53772848 OR id=78871524 OR id=3608561 OR id=85909562 OR id=41702172 OR id=61800503 OR id=57877634 OR id=93407278 OR id=30824340 OR id=13159046 OR id=49055339 OR id=73058078 OR id=983603 OR id=73571456 OR id=51694978 OR id=75136628 OR id=82716874 OR id=83551181 OR id=7964224 OR id=47505945 OR id=92695321 OR id=15885152 OR id=79282709 OR id=18572099 OR id=27392970 OR id=14552787 OR id=19848227 OR id=4518183 OR id=11773920 OR id=22285326 OR id=71605145 OR id=2402625 OR id=63365854 OR id=70973600 OR id=10584706 OR id=83688869 OR id=84268419 OR id=6026005 OR id=36545233 OR id=24462648 OR id=19293921 OR id=17561083 OR id=52105483 OR id=59243514 OR id=35230465 OR id=34650779 OR id=30053489 OR id=24225251 OR id=59642405 OR id=81933853 OR id=94495716 OR id=26364324 OR id=25980634 OR id=5579237 OR id=14569289 OR id=89417845 OR id=71178959 OR id=4143920 OR id=20467990 OR id=53316808 OR id=21288525 OR id=82249537 OR id=37737589 OR id=44712689 OR id=36788133 OR id=15668654 OR id=4697556 OR id=63785060 OR id=11555169 OR id=36401204 OR id=92276179 OR id=4135929 OR id=75453019 OR id=28231031 OR id=8649240 OR id=11576980 OR id=20262028 OR id=56242424 OR id=11305608 OR id=5655216 OR id=90240601 OR id=28569373 OR id=5296027 OR id=10739594 OR id=72751648 OR id=22531251 OR id=12535926 OR id=36347415 OR id=19740655 OR id=69125465 OR id=7523885 OR id=88128548 OR id=88830806 OR id=25010302 OR id=29411467 OR id=99614288 OR id=32646290 OR id=16592563 OR id=69036910 OR id=32604729 OR id=88737786 OR id=90169676 OR id=57646877 OR id=72105460 OR id=40027541 OR id=70362483 OR id=37221415 OR id=25284914 OR id=69691185 OR id=17972978 OR id=1544661 OR id=47324366 OR id=25337670 OR id=91133621 OR id=63697117 OR id=48652228 OR id=18538437 OR id=79966496 OR id=26066529 OR id=65334307 OR id=8305141 OR id=86289387 OR id=20178085 OR id=88836090 OR id=74948034 OR id=14101728 OR id=7837868 OR id=83548120 OR id=65602502 OR id=83129211 OR id=24785681 OR id=65000269 OR id=49140174 OR id=62636621 OR id=31096695 OR id=52276400 OR id=28546681 OR id=83631937 OR id=57100225 OR id=42531528 OR id=28326396 OR id=38641032 OR id=93055463 OR id=20525612 OR id=66073509 OR id=35154065 OR id=29007664 OR id=12600294 OR id=76829494 OR id=73917074 OR id=67226149 OR id=12478806 OR id=39842542 OR id=70312958 OR id=82792046 OR id=49668650 OR id=46280815 OR id=96555182 OR id=22966062 OR id=83158116 OR id=87566530 OR id=66277804 OR id=7944142 OR id=90649884 OR id=64342810 OR id=9881875 OR id=14833854 OR id=82959569 OR id=50523207 OR id=48788762 OR id=3801076 OR id=14677723 OR id=63080506 OR id=96215352 OR id=36302231 OR id=35067168 OR id=11695282 OR id=19447382 OR id=66401373 OR id=40822285 OR id=41406321 OR id=48630216 OR id=78955925 OR id=57194625 OR id=52097877 OR id=16169037 OR id=44834346 OR id=2593695 OR id=29948466 OR id=41842778 OR id=50510473 OR id=39669493 OR id=64590865 OR id=26160800 OR id=94882286 OR id=2703212 OR id=41243905 OR id=89363549 OR id=82819429 OR id=25565895 OR id=86836890 OR id=58385785 OR id=55898457 OR id=99305620OR id=43332680 OR id=98223672 OR id=4494624 OR id=25408421 OR id=28054121 OR id=48197701 OR id=90633404 OR id=25825550 OR id=90631154 OR id=24867226 OR id=61846156 OR id=38911183 OR id=67826056 OR id=10676975 OR id=57116645 OR id=474292 OR id=82387517 OR id=56211477 OR id=46555785 OR id=49282428 OR id=99468990 OR id=81172472 OR id=26720330 OR id=38692582 OR id=96073680 OR id=88412290 OR id=28829489 OR id=1816508 OR id=75321051 OR id=81650509 OR id=23175973 OR id=42008725 OR id=60743468 OR id=52532114 OR id=731909 OR id=77811415 OR id=86804961 OR id=29675484 OR id=33584929 OR id=180367 OR id=93687804 OR id=41093066 OR id=5987495 OR id=27291494 OR id=78229979 OR id=63194139 OR id=34357776OR id=9992084 OR id=22643334 OR id=22407822 OR id=69740170 OR id=29581361 OR id=50036776 OR id=88768091 OR id=82537322 OR id=83709895 OR id=55361776 OR id=90616169 OR id=44595355 OR id=9468440 OR id=54552233 OR id=73496954 OR id=46104486 OR id=92947715 OR id=38522993 OR id=88515232 OR id=57725249 OR id=48507967 OR id=25309486 OR id=91597013 OR id=85635814 OR id=69579638 OR id=68775627 OR id=57556546 OR id=77900275OR id=95965693 OR id=9601780 OR id=5448068 OR id=54075952 OR id=64335883 OR id=80114875 OR id=14793294 OR id=21016639 OR id=1959922 OR id=93176996 OR id=7893733 OR id=51407895 OR id=45849129 OR id=33857790 OR id=30096194 OR id=78021982 OR id=66555961 OR id=15842998 OR id=77678123 OR id=56648395 OR id=8171848 OR id=80152264 OR id=78616680 OR id=80098122 OR id=22882409 OR id=77242219 OR id=3124519 OR id=60865422 OR id=43164198 OR id=43256621 OR id=73261157 OR id=12541949 OR id=49780175 OR id=23167183 OR id=10509251 OR id=41809106 OR id=25655902 OR id=6752559 OR id=39850293 OR id=50992519 OR id=40061483 OR id=84526968 OR id=93056718 OR id=53267125 OR id=53914467 OR id=39404926 OR id=83672449 OR id=21484465 OR id=34147538 OR id=13437853 OR id=74079093 OR id=50400032 OR id=85705998 OR id=7557614 OR id=10300505 OR id=79264856 ORid=65669946 OR id=23899714 OR id=53506926 OR id=36081544 OR id=11113765 OR id=65755643 OR id=5826515 OR id=60392667 OR id=55562374 OR id=98132987 OR id=80904530 OR id=92663352 OR id=7283593 OR id=3709276 OR id=52078745 OR id=84847057 OR id=34235334 OR id=63889320 OR id=70036669OR id=58603533 OR id=27394053 OR id=54766781 OR id=50920854 OR id=80202681 OR id=67618417 OR id=82912294 OR id=20150728 OR id=20042189 OR id=86403320 OR id=38738266 OR id=58393070 OR id=50887299 OR id=12170654 OR id=16212895 OR id=37361223 OR id=13677457 OR id=19503506 OR id=20213757 OR id=84240441 OR id=39618969 OR id=26401150 OR id=47937678 OR id=55871130 OR id=79189571 OR id=5717133 OR id=12444503 OR id=95283334 OR id=14827147 OR id=22008485 OR id=56345882 OR id=43237192 OR id=56980197 OR id=68699371 OR id=46407250 OR id=72120555 OR id=70694039 ORid=46438829 OR id=17774982 OR id=36484024 OR id=138767 OR id=89563532 OR id=54847019 OR id=7815592 OR id=44909604 OR id=50479084 OR id=17462504 OR id=96594465 OR id=58317102 OR id=92426225 OR id=91894699 OR id=4501659 OR id=43315607 OR id=9442814 OR id=19705166 OR id=87751308 OR id=95588126 OR id=92372510 OR id=20281564 OR id=19251355 OR id=10321183 OR id=34573093 OR id=19074704 OR id=84678191 OR id=24383998 OR id=27670253 OR id=50223562 OR id=34091936 OR id=99304371 OR id=32477827 OR id=54273037 OR id=86525073 OR id=73253547 OR id=33316827 OR id=6724062 OR id=76707318 OR id=78171148 OR id=44729510 OR id=16697684 OR id=68966388 OR id=57448392 OR id=51380186 OR id=35344477 OR id=98153122OR id=51825492 OR id=27202774 OR id=26901641 OR id=37527637 OR id=88241695 OR id=15100257 OR id=30418000 OR id=21821200 OR id=95511035 OR id=9289513 OR id=83870196 OR id=54628801 OR id=39402988 OR id=88345504 OR id=84232433 OR id=13925255 OR id=70816934 OR id=6822742 OR id=14400466 OR id=430652 OR id=87397095 OR id=89773413 OR id=10883914 OR id=89939310 OR id=39597573 OR id=49356789 OR id=62857680 OR id=93292662 OR id=55644642 OR id=81922551 OR id=94304087 OR id=63705961 OR id=137763 OR id=22392805 OR id=65195561 OR id=39498904 OR id=22576234 OR id=59467794 OR id=46389072 OR id=66341462 OR id=44602153 OR id=18204976 OR id=45366397 OR id=3880945 OR id=98231882 OR id=27999162 OR id=38209350 OR id=10599910 OR id=77139550 OR id=35114264 OR id=57109708 OR id=93064441 OR id=34801782 OR id=24938667 OR id=84955486 OR id=53018874 OR id=37969943 OR id=64372852 OR id=69596670 OR id=21288762 OR id=12774121 OR id=97588451 OR id=23575359 OR id=10954061 OR id=50363988 OR id=56263940 OR id=61520763 OR id=85096643 OR id=36250068 OR id=19807406 OR id=20984386 OR id=24520668 OR id=44631794 OR id=62587890 OR id=44963362 OR id=7663521 OR id=78505677 OR id=98442373 OR id=90280978 OR id=14494324 OR id=16069861 OR id=11397153 OR id=87726305 OR id=26133866OR id=42024935 OR id=93393929 OR id=72575268 OR id=76384597 OR id=42272046 OR id=81658814 OR id=40811718 OR id=86054463 OR id=35997739 OR id=51075676 OR id=62839927 OR id=68179261 OR id=19292480 OR id=10464999 OR id=6342696 OR id=75842285 OR id=28671096 OR id=30029838 OR id=19617648 OR id=94667632 OR id=75855376 OR id=83477767 OR id=456684 OR id=81197213 OR id=1961395 OR id=79590898 OR id=470693 OR id=64786459 OR id=90138714 OR id=30486571 OR id=75566704 OR id=64467558 OR id=21380112 OR id=17742907 OR id=7733647 OR id=92017 OR id=64615799 OR id=72272722 OR id=66873854 OR id=77198963 OR id=35594848 OR id=42694993 OR id=12431322 OR id=2247181 OR id=11020746 OR id=42416726 OR id=19127785 OR id=95444937 OR id=36842133 OR id=4203521 OR id=48149533 OR id=45322440 OR id=59710953 OR id=38250773 OR id=31370132 OR id=26889920 OR id=45927952 OR id=55298246 OR id=31197238 OR id=44744953 OR id=35531670 OR id=38850041 OR id=29759177 OR id=76433451 OR id=33696500 OR id=2823716 OR id=68574340 OR id=68889919 OR id=35744793 OR id=64772909 OR id=41562277 OR id=72606631 OR id=54617176 OR id=76086087 OR id=61060196 OR id=1593669 OR id=4666059 OR id=44201567 OR id=97015910 OR id=51039786 OR id=47534369 OR id=36899420 OR id=95163693 OR id=34278055 OR id=24361819 OR id=93200909 OR id=29991418 OR id=63172824 OR id=53644148 OR id=61454424 OR id=44726508 OR id=64910883 OR id=31088636 OR id=14005026 OR id=83267869 OR id=28497493 OR id=12406441 OR id=34686539 OR id=70646963 OR id=7687253 OR id=23115957 OR id=64556990 OR id=49701688 OR id=76843379 OR id=22370877 OR id=11199132 OR id=15492661 OR id=72101877 OR id=47154152 OR id=54969058 OR id=96696025 OR id=33567129 OR id=95788960 OR id=13301506 OR id=38695877 OR id=52992551 OR id=37817234 OR id=82136809 OR id=28111091 OR id=84977065 OR id=93404791 OR id=56350318 OR id=27576451 OR id=84170153 OR id=37381626 OR id=22432144 OR id=35119973 OR id=23922989 OR id=98961080 OR id=14336913 OR id=49612713 OR id=47410677 OR id=41559348 OR id=64216475 OR id=75502736 OR id=16203656 OR id=81726720 OR id=64541981 OR id=82181762 OR id=95869963 OR id=1086041 OR id=76856852 OR id=99484886 OR id=47292021 OR id=99746735 OR id=79082859 OR id=67416188 OR id=46391963 OR id=58631281 OR id=80994168 OR id=9464550 OR id=5851058 OR id=16534935 OR id=63307701 OR id=91875109 OR id=18716507 OR id=15870646 OR id=6003995 OR id=836024 OR id=35610568 OR id=39574140 OR id=76244639 OR id=83403189 OR id=51252728 OR id=6516065 OR id=94907007 OR id=81605606 OR id=40398075 OR id=40258386 OR id=6692981 OR id=50852074 OR id=2869416 OR id=97682971 OR id=44427361 OR id=9608914 OR id=58464559 OR id=81806036 OR id=20047387 OR id=66264452 OR id=58063775 OR id=54179837 OR id=48463792 OR id=17877188 OR id=31718426 OR id=64192249 OR id=35574859 OR id=3671766 ORid=88905164 OR id=78137697 OR id=46929619 OR id=21063327 OR id=83078770 OR id=93293821 OR id=41618319 OR id=3832324 OR id=91310612 OR id=79854291 OR id=68734227 OR id=8826717 OR id=80881657 OR id=95208907 OR id=7079422 OR id=30037415 OR id=5494004 OR id=44809486 OR id=97620027 OR id=35689182 OR id=13120783 OR id=26108678 OR id=1537176 OR id=16538727 OR id=50841024 OR id=36515680 OR id=82635278 OR id=11112660 OR id=16276555 OR id=72997511 OR id=93487848 OR id=88201238 OR id=53997085 OR id=15198916 OR id=61214583 OR id=78412499 OR id=3585265 OR id=1402827 OR id=56445518 OR id=47661453 OR id=25615629 OR id=58263458 OR id=62155263 OR id=46608555 OR id=15822703 OR id=82285214 OR id=76021596 OR id=84571697 OR id=45999350 OR id=40074628 OR id=8219220 OR id=5429523 OR id=74024203 OR id=22354037 OR id=17605466 OR id=60436920 OR id=52777032 OR id=65801717 OR id=43656316 OR id=10424270 OR id=48035786 OR id=29493228 OR id=83897372 OR id=62101275 OR id=84793857 OR id=56894828 OR id=70636689 OR id=72497148 OR id=67388694 OR id=68146510 OR id=64298548 OR id=97117498 OR id=25553211 OR id=54226533 OR id=90395845OR id=24172623 OR id=91712292 OR id=98280822 OR id=54042497 OR id=25032894 OR id=6833135 OR id=39011254 OR id=9837753 OR id=63507766 OR id=26747954 OR id=45941264 OR id=99955245 OR id=80051546 OR id=78510759 OR id=71322333 OR id=92407609 OR id=95809491 OR id=18999217 OR id=23430377 OR id=11861293 OR id=42583098 OR id=24163209 OR id=11358738 OR id=3237302 OR id=3176665 OR id=87151132 OR id=2789150 OR id=63905882 ORid=59864282 OR id=3673596 OR id=19570439 OR id=22883042 OR id=72375525 OR id=51614404 OR id=47526636 OR id=98443133 OR id=99140135 OR id=33855918 OR id=28333489 OR id=81416033 OR id=2670097 OR id=4897577 OR id=24439616 OR id=36643479 OR id=40817600 OR id=76022791 OR id=40072872OR id=95193435 OR id=96967607 OR id=24983145 OR id=49883271 OR id=94602753 OR id=83555050 OR id=85455145 OR id=34563229 OR id=72328311 OR id=12002151 OR id=71481181 OR id=72998351 OR id=1489188 OR id=38426973 OR id=91893116 OR id=61594591 OR id=89693630 OR id=6268166 OR id=20056665 OR id=62169880 OR id=17143472 OR id=35103925 OR id=22452590 OR id=54272289 OR id=34236829 OR id=78028543 OR id=84474414 OR id=40386926OR id=50550952 OR id=49413559 OR id=48781941 OR id=22927237 OR id=44447815 OR id=29960478 OR id=47578119 OR id=10192558 OR id=87733936 OR id=88699383 OR id=38808712 OR id=79944807 OR id=84014713 OR id=31865463 OR id=72617685 OR id=19557568 OR id=47865990 OR id=39069638 OR id=20086122 OR id=1777562 OR id=29018078 OR id=78358083 OR id=94561719 OR id=46281152 OR id=99789008 OR id=86929490 OR id=16534451 OR id=55989144 OR id=52455669 OR id=54561585 OR id=97379646 OR id=20416183 OR id=87617750 OR id=76115505 OR id=3282482 OR id=8383619 OR id=45456319 OR id=29576432 OR id=67750627 OR id=61736333 OR id=33745442 OR id=51502165 OR id=35349384 OR id=78106651 OR id=23232822 OR id=94851387 OR id=78254073 OR id=82406754 OR id=10317954 OR id=70125940 OR id=45067526 OR id=27061875 OR id=25640164 OR id=52574899 OR id=93819227 OR id=93789607 OR id=96122951 OR id=31673246 OR id=70431904 OR id=54067896 OR id=37146857 OR id=37817889 OR id=14058940 OR id=60710246 OR id=64844350 OR id=91604383 OR id=71972005 OR id=13888349 OR id=19093493 OR id=27397281 OR id=61085409 OR id=66529387 OR id=82761299 OR id=72236310 OR id=19277077 OR id=96599501 OR id=68304096 OR id=48292937 OR id=97503321 OR id=88011133 OR id=29224803 OR id=79782945 OR id=79965966 OR id=83716914 OR id=90432214 OR id=48938902 OR id=12498489 OR id=30246261 OR id=91624049 OR id=68652396 OR id=23677785 OR id=44084687 OR id=3865123OR id=37823170 OR id=45287730 OR id=38784682 OR id=28058351 OR id=68226368 OR id=61569897 OR id=44737876 OR id=70575908 OR id=25568463 OR id=24668386 OR id=88650569 OR id=35559584 OR id=1897737 OR id=77844785 OR id=29780669 OR id=84004602 OR id=29029776 OR id=91003545 OR id=48058106 OR id=9463847;

测试结果如下：
第一种情况，ID列为主键的情况，4组测试执行计划一样，执行的时间也基本没有区别。
A组or和in的执行时间： or的执行时间为：0.002s     in的执行时间为：0.002s
B组or和in的执行时间： or的执行时间为：0.004s     in的执行时间为：0.004s
C组or和in的执行时间： or的执行时间为：0.006s     in的执行时间为：0.005s
D组or和in的执行时间： or的执行时间为：0.018s     in的执行时间为：0.014s

第二种情况，ID列为一般索引的情况，4组测试执行计划一样，执行的时间也基本没有区别。
A组or和in的执行时间： or的执行时间为：0.002s     in的执行时间为：0.002s
B组or和in的执行时间： or的执行时间为：0.006s     in的执行时间为：0.005s  
C组or和in的执行时间： or的执行时间为：0.008s     in的执行时间为：0.008s
D组or和in的执行时间： or的执行时间为：0.021s     in的执行时间为：0.020s 

第三种情况，ID列没有索引的情况，4组测试执行计划一样，执行的时间也基本没有区别。
A组or和in的执行时间： or的执行时间为：5.016s      in的执行时间为：5.071s
B组or和in的执行时间： or的执行时间为：1min 02s     in的执行时间为：5.018s
C组or和in的执行时间： or的执行时间为：1min 55s     in的执行时间为：5.018s
D组or和in的执行时间： or的执行时间为：6min 17s     in的执行时间为：5.057s

结论：

    从上面的测试结果，可以看出如果in和or所在列有索引或者主键的话，or和in没啥差别，执行计划和执行时间都几乎一样。如果in和or所在列没有索引的话，性能差别就很大了。在没有索引的情况下，随着in或者or后面的数据量越多，in的效率不会有太大的下降，但是or会随着记录越多的话性能下降非常厉害，从第三中测试情况中可以很明显地看出了，基本上是指数级增长。
   因此在给in和or的效率下定义的时候，应该再加上一个条件，就是所在的列是否有索引或者是否是主键。如果有索引或者主键性能没啥差别，如果没有索引，性能差别不是一点点！

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412月/13关

MYSQL在默认的情况下查询不区分大小写

发布在 邵珠庆

MYSQL在默认的情况下查询是不区分大小写的，例如：

mysql> create table t1(
    -> name varchar(10));
Query OK, 0 rows affected (0.09 sec)

mysql> insert into t1 values('you'),('You'),('YOU');
Query OK, 3 rows affected (0.05 sec)
Records: 3  Duplicates: 0  Warnings: 0
对这个表，缺省情况下，下面两个查询的结果是一样的：


mysql> select * from t1 where name = 'you';
+------+
| name |
+------+
| you  |
| You  |
| YOU  |
+------+
3 rows in set (0.00 sec)

mysql> select * from t1 where name = 'YOU';
+------+
| name |
+------+
| you  |
| You  |
| YOU  |
+------+
3 rows in set (0.00 sec)

如果想让MYSQL知道你输入的字母是大写还是小写的，修改表：

mysql> alter table t1 change name name varchar(10) binary;
Query OK, 3 rows affected (0.20 sec)
Records: 3  Duplicates: 0  Warnings: 0


mysql> select * from t1 where name = 'you';
+------+
| name |
+------+
| you  |
+------+
1 row in set (0.00 sec)

mysql> select * from t1 where name = 'YOU';
+------+
| name |
+------+
| YOU  |
+------+
1 row in set (0.00 sec)

如果你只是想在SQL语句中实现的话：

mysql> select * from t1 where name = binary 'YOU';
+------+
| name |
+------+
| YOU  |
+------+
1 row in set (0.02 sec)

mysql> select * from t1 where name = binary 'you';
+------+
| name |
+------+
| you  |
+------+
1 row in set (0.00 sec)

 

如果不想这么麻烦而想服务一开启就让大小写一致的话：
可以修改my.ini或者my.cnf
[mysqld]
 lower_case_table_names=1
（0：区分；1：不区分）
然后重启MYSQL服务。

mysql> show variables like '%case_table%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| lower_case_table_names | 1     |
+------------------------+-------+
1 row in set (0.00 sec)
注：WINDOWS系统不用修改，系统默认就是1
LINUX 系统默认是0。因为LINUX下的脚本都是区分大小写的。 

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1310月/13关

mysql数据库数据变化实时监控

发布在 邵珠庆

对于二次开发来说，很大一部分就找找文件和找数据库的变化情况

对于数据库变化。还没有发现比较好用的监控数据库变化监控软件。

今天，我就给大家介绍一个如何使用mysql自带的功能监控数据库变化

1、打开数据库配置文件my.ini （一般在数据库安装目录）（D:\MYSQL）

2、在数据库的最后一行添加 log=log.txt  代码

3、重启mysql数据库

4、去数据库数据目录 我的是(D:\MYSQL\data) 你会发现多了一个log.txt文件

我的是在C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.5\data

测试：
1、对数据库操作
2、查看log.txt文件内容 如果发现有变化说明你就可以监控到mysql数据库的变化
数据库的查询 删除 更新 插入都可以查到

希望本篇文章可以帮助大家更快的二次开发 ^_^

日志文件类型概述：
1．错误日志 记录启动、运行或停止mysqld时出现的问题。
My.ini配置信息：
#Enter a name for the error log file. Otherwise a default name will be used.
#log-error=d:/mysql_log_err.txt
2．查询日志 记录建立的客户端连接和执行的语句。
My.ini配置信息：
#Enter a name for the query log file. Otherwise a default name will be used.
#log=d:/mysql_log.txt
3．更新日志 记录更改数据的语句。不赞成使用该日志。
My.ini配置信息：
#Enter a name for the update log file. Otherwise a default name will be used.
#log-update=d:/mysql_log_update.txt
4．二进制日志 记录所有更改数据的语句。还用于复制。
My.ini配置信息：
#Enter a name for the binary log. Otherwise a default name will be used.
#log-bin=d:/mysql_log_bin
5．慢日志 记录所有执行时间超过long_query_time秒的所有查询或不使用索引的查询。
My.ini配置信息：
#Enter a name for the slow query log file. Otherwise a default name will be used.
#long_query_time =1
#log-slow-queries= d:/mysql_log_slow.txt

在linux下：
Sql代码

1. # 在[mysqld] 中輸入
2. #log
3. log-error=/usr/local/mysql/log/error.log
4. log=/usr/local/mysql/log/mysql.log
5. long_query_time=2
6. log-slow-queries= /usr/local/mysql/log/slowquery.log

# 在[mysqld] 中輸入 #log log-error=/usr/local/mysql/log/error.log log=/usr/local/mysql/log/mysql.log long_query_time=2 log-slow-queries= /usr/local/mysql/log/slowquery.log

windows下:
Sql代码

1. # 在[mysqld] 中輸入
2. #log
3. log-error="E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/error.log"
4. log="E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/mysql.log"
5. long_query_time=2
6. log-slow-queries= "E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/slowquery.log"

# 在[mysqld] 中輸入 #log log-error="E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/error.log" log="E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/mysql.log" long_query_time=2 log-slow-queries= "E:/PROGRA~1/EASYPH~1.0B1/mysql/logs/slowquery.log"

开启慢查询
long_query_time =2 --是指执行超过多久的sql会被log下来，这里是2秒
log-slow-queries= /usr/local/mysql/log/slowquery.log --将查询返回较慢的语句进行记录

log-queries-not-using-indexes = nouseindex.log --就是字面意思，log下来没有使用索引的query

log=mylog.log --对所有执行语句进行记录

日志的存放:默认情况下,当开启时,所有的日志都存放在DataDir目录下. 如果没有指定名称的话，它会以后主机名为名称. 如主机名为songcomputer,则相关就的日志为songcomputer.log文件.

Mysql日志的关闭与开启：

使用以下命令查看是否启用了日志 ：mysql>show variables like 'log_%’; 

凡Value值为OFF的表示未开启服务，若要开启只需要将上的my.ini配置信息写入(my.ini为mysql安装目录下)，然后去掉前面的“#”
号，再重启mysql服务。OK，现在会看到指定的日志文件已创建。相反地，若要停止mysql日志服务，只需要将my.ini中对应的配置信息去掉即
可。

>>>>相应的使用慢日志查询

手动的去读取慢日志以及修改慢日志的时间 show variables like 'long%' 会得到慢日志的时间

进行设置慢日志的值 set long_query_time =2 侧重的二进制文件

二进制日志：

从概述中我可以看到my.ini配置信息的log-bin没有指定文件扩展名，这是因为即使你指定上扩展名它也不使用。当mysql创建二进制日志文件
时，首先创建一个以“mysql_log_bin”为名称，以“.index”为后缀的文件；再创建一个以“mysql_log_bin”为名称，以
“.000001”为后缀的文件。当mysql服务重新启动一次以“.000001”为后缀的文件会增加一个，并且后缀名加1递增；如果日志长度超过了
max_binlog_size的上限（默认是1G）也会创建一个新的日志文件；使用flush
logs（mysql命令符）或者执行mysqladmin –u –p flush-logs（windows命令提示符）也会创建一个新的日志文件。

既然写入的都是二进制数据，用记事本打开文件是看不到正常数据的，那怎么查看呢？

使用BIN目录下mysqlbinlog命令，如：

Bin>mysqlbinlog d:/mysql_log/mysql_bin.000001

Bin>mysqlbinlog d:/mysql_log/mysql_bin.000002

Bin>mysqlbinlog d:/mysql_log/mysql_bin.000003

Bin>mysqlbinlog d:/mysql_log/mysql_bin.000004

Bin>mysqlbinlog d:/mysql_log/mysql_bin.000005

使用SQL语句也可查看mysql创建的二进制的文件目录：Mysql> show master logs; 

查看当前二进制文件状态：mysql> show master status;  

至于准确的看懂日志文件，还需要读者仔细阅读，深深体会，这里就不再奥述了！

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