查询所有数据库占用磁盘空间大小的SQL语句：

select TABLE_SCHEMA, concat(truncate(sum(data_length)/1024/1024,2),' MB') as data_size,

concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size

from information_schema.tables

group by TABLE_SCHEMA

order by data_length desc;

查询单个库中所有表磁盘占用大小的SQL语句：

select TABLE_NAME, concat(truncate(data_length/1024/1024,2),' MB') as data_size,

concat(truncate(index_length/1024/1024,2),' MB') as index_size

from information_schema.tables where TABLE_SCHEMA = 'TestDB'

group by TABLE_NAME

order by data_length desc;