mysql> UPDATE table_name SET blob_column=LOAD_FILE("/tmp/picture") WHERE id=1; MySQL必要时自动变换数字为字符串,并且反过来也如此: mysql> SELECT 1+"1"; -> 2 mysql> SELECT CONCAT(2,' test'); -> '2 test' 如果你想要明确地变换一个数字到一个字符串,把它作为参数传递到CONCAT()。 如果字...
mysql> select 'apa' REGEXP '^(pi|apa)$'; -> 1(表示匹配) mysql> select 'pi' REGEXP '^(pi|apa)$'; -> 1(表示匹配) mysql> select 'pix' REGEXP '^(pi|apa)$'; -> 0(表示不匹配) (abc)* 匹配任意多个abc(包括空串) mysql> select 'pi' REGEXP '^(pi)*$'; -> 1(表示匹配) ...
例3:select * from score where sid like '9634' 例4:select * from student where class in (select class from student where name='陈小小') (2)INSERT插入语句 语法:INSERT INTO <表名> [(<字段名1> [,<字段名2>, ...])] VALUES (<常量1> [,<常量2>, ...]) 语法:INSERT INTO <表名>...
-函数体由多条可用的mysql语句,流程控制,变量声明等语句构成。-多条语句应该使用begin...end语句块包含。-一定要有return返回值语句。--删除DROPFUNCTION[IF EXISTS]function_name;--查看SHOWFUNCTIONSTATUSLIKE'partten'SHOWCREATEFUNCTIONfunction_name;--修改ALTERFUNCTIONfunction_name 函数选项--// 存储过程,自定义...
IN:内层查询语句返回一个数据列,这个数据列里的值将用于操作外层查询语句进行。 实例: 数据源:表格Pastavg【数据列Tue_ave有数字3,5,6】,S_order【订单表】 查询订单信息:当S_order里的S_Teu大于(Any/Some)任意Tue_ave的值 mysql> select * from s_order where S_teu> any (select Tue_avg from Past...
[Err] 1235 - This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'...低版本中mysql不支持在limit语句中有子查询所以只要在有limit的语句里再向外包一层 ( select t.ACTIVITY_ID from (select DISTINCT(e.ACTIVITY_ID...oe.ACTIVITY_ID IN ( SELECT t.ACTIVITY_I...
本文从源码角度分析了一下MySQL中 union 和 union all 的区别;得出了以下结论: union 和 union all 都会创建临时表, 但是又不太一样; 二者的查询计划不一样;union 默认会创建一个以返回列作为 key 的临时表, 所谓过滤就是将数据插入这个临时表; 临时表装数据的容器实际上是一个 unordered_set; 有一种存储引...
Notes This is the inverse of the CHAR function. ASIN Syntax ASIN(number) Output Number (angle in radians) Definition Returns the arcsine (angle) of a given <number>. Example ASIN(1) = 1.5707963267949 Notes The inverse function, SIN, takes the angle in radians as the argument and return...
MySQL Worklogs are design specifications for changes that may define past work, or be considered for future development. WL#1763: Avoid creating temporary table in UNION ALL Status: Complete Description High Level Architecture Low Level Design ...
(Supported in all NDB releases based on MySQL 8.0) --connect-string=connection_string, -c connection_string Same as --ndb-connectstring (Supported in all NDB releases based on MySQL 8.0) --core-file Write core file on error; used in debugging ...