查询所有数据库占用空间大小

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;

查询整个库里面所有表的大小

select table_name,table_rows,data_length+index_length,
concat(round((data_length+index_length)/1024/1024,2),'MB') 
data from information_schema.tables where table_schema='你要查询的库'

查询整个库里面所有表的信息

select * from information_schema.tables 
where table_schema='你要查询的库';

查询某个数据库内各个表的容量大小

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 = '库名'
    group by TABLE_NAME
    order by data_length desc;