MySQL information_schema

-- 查询当前连接下的所有数据库
SHOW DATABASES


-- 查询当前数据库下的表清单
select table_schema,TABLE_NAME,TABLE_TYPE,TABLE_COMMENT,TABLE_ROWS,TABLE_CATALOG,TABLE_COLLATION 
from information_schema.tables
where table_schema = 'ekzc_audit' 

-- 查看表字段
SELECT COLUMN_NAME,COLUMN_COMMENT,COLUMN_TYPE,COLUMN_DEFAULT,TABLE_SCHEMA
FROM  `information_schema`.`COLUMNS` 
WHERE  `TABLE_SCHEMA` =  'zt_finance_erp_account'
AND  `TABLE_NAME` =  'time_task' 
ORDER BY COLUMN_NAME




SELECT COLUMN_NAME,COLUMN_COMMENT,COLUMN_TYPE,COLUMN_DEFAULT,TABLE_SCHEMA
FROM  `information_schema`.`COLUMNS` 
WHERE  `TABLE_SCHEMA` =  'zt_finance_erp_account'
AND  `TABLE_NAME` =  'time_task' 
ORDER BY COLUMN_NAME

-- 查看table_schema下面所有表的空间占用
SELECT table_name,
 concat( round( sum( data_length / 1024 / 1024 ), 2 ), 'MB' ) AS data_length_MB,
 concat( round( sum( index_length / 1024 / 1024 ), 2 ), 'MB' ) AS index_length_MB 
FROM
 information_schema.TABLES  
where table_schema = 'ekzc_audit'
GROUP by table_name;