标签：exp out ati row 表示 语句 时间 HERE --
需求描述:
今天在查mysq关于连接数的问题,想要通过一个show variables命令同时查出来多个值.在此记录下.
操作过程:
1.通过show variables语句的like可以匹配多个值或者某个值
mysql> show variables like ‘max_connections‘; #这里默认的就是对Variable_name进行匹配,这里是准确匹配. +-----------------+-------+ | Variable_name | Value | +-----------------+-------+ | max_connections | 151 | +-----------------+-------+ 1 row in set (0.01 sec) mysql> show variables like ‘socket‘; +---------------+-----------------+ | Variable_name | Value | +---------------+-----------------+ | socket | /tmp/mysql.sock | +---------------+-----------------+ 1 row in set (0.00 sec)
2.通过%通配符进行匹配
mysql> show variables like ‘%connec%‘; #通过百分号(%)这个通配符进行匹配,可以匹配多项. +-----------------------------------------------+-------------------+ | Variable_name | Value | +-----------------------------------------------+-------------------+ | character_set_connection | latin1 | | collation_connection | latin1_swedish_ci | | connect_timeout | 10 | | disconnect_on_expired_password | ON | | init_connect | | | max_connect_errors | 100 | | max_connections | 151 | | max_user_connections | 0 | | performance_schema_session_connect_attrs_size | 512 | +-----------------------------------------------+-------------------+ 9 rows in set (0.00 sec)
mysql> show variables like ‘innodb_thread%‘; #%通配符在结束处.
+---------------------------+-------+
| Variable_name | Value |
+---------------------------+-------+
| innodb_thread_concurrency | 0 |
| innodb_thread_sleep_delay | 10000 |
+---------------------------+-------+
2 rows in set (0.00 sec)
mysql> show variables like ‘%version‘; #%通配符在开始处.
+------------------+---------------+
| Variable_name | Value |
+------------------+---------------+
| innodb_version | 5.7.21 |
| protocol_version | 10 |
| tls_version | TLSv1,TLSv1.1 |
| version | 5.7.21-log |
+------------------+---------------+
4 rows in set (0.00 sec)
3.使用where子句进行匹配查询
mysql> show variables where variable_name = ‘version‘; +---------------+------------+ | Variable_name | Value | +---------------+------------+ | version | 5.7.21-log | +---------------+------------+ 1 row in set (0.01 sec) mysql> show variables where variable_name in (‘version‘,‘innodb_version‘); +----------------+------------+ | Variable_name | Value | +----------------+------------+ | innodb_version | 5.7.21 | | version | 5.7.21-log | +----------------+------------+ 2 rows in set (0.00 sec) mysql> show variables where value like ‘5.7%‘; +----------------+------------+ | Variable_name | Value | +----------------+------------+ | innodb_version | 5.7.21 | | version | 5.7.21-log | +----------------+------------+ 2 rows in set (0.00 sec) mysql> show variables where variable_name = ‘version‘ and value = ‘5.7‘; Empty set (0.00 sec) mysql> show variables where variable_name = ‘version‘ and value like ‘5.7%‘; +---------------+------------+ | Variable_name | Value | +---------------+------------+ | version | 5.7.21-log | +---------------+------------+ 1 row in set (0.00 sec)
备注:使用where子句的方式就和在SQL语句中使用where的方式是一样的.
小结:
文档创建时间:2018年7月17日11:33:27
mysql中使用show variables同时查询多个参数值?show variables的使用?
标签：exp out ati row 表示 语句 时间 HERE --
原文地址：https://www.cnblogs.com/chuanzhang053/p/9322550.html
