查询数据库大小 查询所有数据库的总大小查询数据库大小：use information_schema; select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES;统计一下所有库数据量 每张表数据量=AVG_ROW_LENGTH*TABLE_ROWS+INDEX_LENGTHSELECT SUM(AVG_ROW_LENGTH*TABLE_ROWS+INDEX_LENGTH)/1024/1024 AS total_mb FROM information_schema.TABLES 统计每个库大小：SELECT table_schema,SUM(AVG_ROW_LENGTH*TABLE_ROWS+INDEX_LENGTH)/1024/1024 AS total_mb FROM information_schema.TABLES group by table_schema; 查看指定数据库的大小use information_schema; select concat(round(sum(DATA_LENGTH/1024/1024),2),'MB') as data from TABLES where table_schema='test';1.查看所有数据库各容量大小select table_schema as '数据库', sum(table_rows) as '记录数', sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)', sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)' from information_schema.tables group by table_schema order by sum(data_length) desc, sum(index_length) desc;2.查看所有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 order by data_length desc, index_length desc;3.查看指定数据库容量大小例：查看mysql库容量大小select table_schema as '数据库', sum(table_rows) as '记录数', sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)', sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)' from information_schema.tables where table_schema='mysql';　4.查看指定数据库各表容量大小例：查看mysql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='mysql' order by data_length desc, index_length desc;