用SQL命令查看Mysql数据库大小

-- 1. 进入information_schema 数据库（存放了其他的数据库的信息）
use information_schema;

-- 2. 查询所有数据的大小：
select concat(round(sum(data_length/1024/1024),2),‘MB‘) as data 
from information_schema.tables
;

-- 3. 查看实例下所有数据库的空间占用情况
select 
     table_schema
    ,concat(round(sum(data_length/1024/1024),2),‘MB‘) as data 
from information_schema.tables 
where table_schema like ‘db_name_%‘ 
group by table_schema
;

-- 4.查看指定数据库的大小：
select concat(round(sum(data_length/1024/1024),2),‘MB‘) as data 
from information_schema.tables 
where table_schema=‘home‘
;

-- 5. 查看指定数据库下的所有表的空间占用情况
select table_name,round(sum(data_length/1024/1024),2) as size 
from information_schema.tables 
where table_schema=‘mycommunity_zhhy_1‘
group by table_name
order by size
;

-- 6. 查看指定数据库的某个表的大小
select concat(round(sum(data_length/1024/1024),2),‘MB‘) as data 
from information_schema.tables 
where table_schema=‘home‘ and table_name=‘members‘
;