-- 所有的表
select * from infomation.schema.tables;  
-- dbname库下的表
select * from infomation.schema.tables where table_schema=‘dbname‘; 

-- 表名 表注释 表数据大小  索引量
select 
table_name,
table_comment,
concat(truncate(data_length/1024/1024,2),‘MB‘), 
concat(truncate(index_length/1024/1024,2),‘MB‘)
from infomation.shcema.tables where table.schema=‘dbname‘;