1.查询出的一列数据(行业) 转成成一条数据以逗号分开GROUP_CONCAT
2.查询id在一个逗号分开的字段内用FIND_IN_SET
--》》》
sql: select GROUP_CONCAT(name) as industruName from industry where FIND_IN_SET(id,'4,5,6')
3.数据转变case orgType WHEN 'virtual' THEN 0 END AS orgType
4.如果一个字段为空则返回另一个字段ifnull(u2.weixin_nickname,u2.phone)
5.查询的字段中与另一个表的一个字段拼接sql: select c.isFrozen,concat((SELECT `value` FROM dictionary WHERE `key` = 'static_resource_server_name'),c.imgUrl) AS logoUrl from table
6.select * from information_schema.INNODB_LOCKS查询锁
7.show status like '%lock%'
8.show processlist ;
9.SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;
10.SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX;