select concat(round(sum(data_length/1024/1024),2),'MB') as data from information_schema.tables where table_schema='DB_Name';

SELECT
    concat(ROUND(SUM(data_length / 1024 / 1024), 2), 'MB') AS data
FROM
    information_schema.tables
WHERE
    table_schema = 'DB_Name'
    AND table_name = 'Table_Name';

SELECT table_schema AS '数据库', table_name AS '表名', table_rows AS '记录数',
TRUNCATE(data_length / 1024 / 1024, 2) AS '数据容量(MB)',
TRUNCATE
    (index_length / 1024 / 1024, 2) AS '索引容量(MB)'
FROM
    information_schema.tables
WHERE
    table_schema = 'DB_Name'
ORDER BY
    data_length DESC,
    index_length DESC;