SHOW CREATE PROCEDURE – 显示已经创建的存储过程,创建时的语句 mysql>SHOW CREATE PROCEDURE test.simpleproc\G***1. row ***Procedure: simpleproc-存储过程的名字 sql_mode: Create Procedure: CREATE PROCEDURE `simpleproc`(OUT param1 INT) BEGIN SELECT COUNT(*) INTO param1 FROM t; END character_set...
| Variable_name | Value | +———+———+ | key_buffer_size | 536870912 | +———-+———+ key_buffer_size为512MB,我们再看一下key_buffer_size的使用情况: mysql> show global status like ‘key_read%‘; +———+———-+ | Variable_name | Value | +———+———-+ | Key_re...
SQLSTATE [VALUE] sqlstate_value| mysql_error_code; 其中,condition_name 表示条件的名称。condition_value 表示条件的类型,有sqlstate_value参数和mysql_error_code参数,都可以表示MySQL的错误。sqlstate_value表示长度为5的字符串类型错误代码,mysql_error_code表示数值类型错误代码。 例如ERROR 1146(42S02)中,sqls...
AI代码解释 mysql>show variables like'wait_timeout';+---+---+|Variable_name|Value|+---+---+|wait_timeout|28800|+---+---+1rowinset(0.00sec) 当然,我们自己也可以手动断开空闲的连接,使用的是 kill connection + id 的命令。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 mysql>kill c...
mysql> show variables like "profiling"; +---+---+ | Variable_name | Value | +---+---+ | profiling | ON | +---+---+ 1 row in set (0.00 sec) Value的取值范围有两个:其中 ON 为开启状态,OFF为关闭状态。 值得注意的是:通过上述命令开启后仅在当前会话有效。 show profiles show profi...
mysql> select VARIABLE_NAME, VARIABLE_VALUE, concat(VARIABLE_VALUE/1024/1024,' MB') AS VARIABLE_VALUE_MB from information_schema.SESSION_VARIABLES where variable_name in ('innodb_buffer_pool_size','innodb_log_buffer_size','innodb_additional_mem_pool_size','key_buffer_size','query_cache_size...
@b := SELECT key,value+(SELECT * FROM @a) FROM t2 WHERE key >10000; --t2表中value值与@a中的值进行计算。 SELECT * FROM @b; 示例 脚本模式SQL示例如下。 CREATE TABLE IF NOT EXISTS dest(key STRING, value BIGINT) PARTITIONED BY (d STRING); CREATE TABLE IF NOT EXISTS dest2(key STR...
INSERT INTO dbo.Points (PointValue) VALUES (CONVERT(Point, '3,4')); INSERT INTO dbo.Points (PointValue) VALUES (CONVERT(Point, '1,5')); INSERT INTO dbo.Points (PointValue) VALUES (CAST ('1,99' AS Point)); 插入来自其他表的数据 本节中的示例说明将行从一个表插入另一个表的方法。
Is a declared variable that is set to the value returned by expression. SET @variable = column = expression sets the variable to the same value as the column. This differs from SET @variable = column, column = expression, which sets the variable to the pre-update value of the column. ...
Is a declared variable that is set to the value returned by expression. SET @variable = column = expression sets the variable to the same value as the column. This differs from SET @variable = column, column = expression, which sets the variable to the pre-update value of the column. ...