mysql查看数据库和表的占用空间大小

SELECT
    * 
FROM
    information_schema.TABLES 
WHERE
    TABLE_SCHEMA = '{db_name}' 
    AND table_name = '{tab_name}';

SELECT
    concat(round(sum( data_length / 1024 / 1024 ),2 ),'MB' ) 
FROM
    information_schema.PARTITIONS 
WHERE
    table_schema = 'db_name' 
    AND table_name = 'tab_name';