mysql一些基本数据查询

1 查询指定数据库的使用存储空间

SELECT sum(DATA_LENGTH+INDEX_LENGTH)/1024/1024 FROM TABLES WHERE TABLE_SCHEMA='wechat';

2查询表占用的存储空间

SELECT sum(DATA_LENGTH+INDEX_LENGTH)/1024/1024 FROM TABLES WHERE TABLE_SCHEMA='wechat' and table_name='ims_stat_msg_history'

3 查询表的记录数

use information_schema;

select table_name,table_rows from  tables order by table_rows desc;