查看mysql數據庫大小

進去指定schema 數據庫（存放了其他的數據庫的信息）

use information_schema;

查詢所有數據的大小

select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES;

查看指定數據庫的大小，比如說：數據庫device

select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES where table_schema='device';

查看指定數據庫的表的大小，比如說：數據庫device 中device_test表

select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES where table_schema='device' and table_name='device_test';