MySQL查询库/表大小

查所有库：
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;

 
查单独某个库：
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'   -- 注意将SQL语句中的TestDB换成你自己的数据库名称即可！
group by TABLE_NAME 
order by data_length desc;