常用sql语句整理

1.开/关 外键约束

-- 关
SET FOREIGN_KEY_CHECKS = 0;
-- 开
SET FOREIGN_KEY_CHECKS = 1;

2.查看表的容量大小

use information_schema;
SELECT (`DATA_LENGTH`+ `INDEX_LENGTH`)/1024/1024/1024  as `table_data_size`  from `TABLES` WHERE TABLE_NAME ='t_dragon_temperature_capture_flow'

3.查看数据库版本

select version()

4.查看外键引用关系

select * from INFORMATION_SCHEMA.KEY_COLUMN_USAGE  where REFERENCED_TABLE_NAME='t_dragon_mini_course'