1.查看数据库使用大小

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

2.查看表使用大小

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';

3.查看指定数据库各表容量大小

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;