mysql 常用语句
1、查询表的所有字段
select COLUMN_NAME,data_type, column_comment from information_schema.COLUMNS where table_name = 'roles_user' and table_schema = 'cmdb';
2、查询没有主键的表
SELECT
a.TABLE_SCHEMA,
a.TABLE_NAME
FROM
(
SELECT
TABLE_SCHEMA,
TABLE_NAME
FROM
information_schema.TABLES
WHERE
TABLE_SCHEMA IN ( 'cmdb', 'mirror', 'deploy_proxy', 'index_proxy' )) AS a
LEFT JOIN (
SELECT
TABLE_SCHEMA,
TABLE_NAME
FROM
information_schema.TABLE_CONSTRAINTS
WHERE
CONSTRAINT_TYPE = 'PRIMARY KEY'
AND TABLE_SCHEMA IN ( 'cmdb', 'mirror', 'deploy_proxy', 'index_proxy' )) AS b
ON a.TABLE_SCHEMA = b.TABLE_SCHEMA
AND a.TABLE_NAME = b.TABLE_NAME
WHERE
b.TABLE_NAME IS NULL;
3、创建联合主键
ALTER TABLE table_name ADD PRIMARY KEY(字段A,字段B,字段C);
4、mysql登录
mysql -u root -h 10.12.1.110 -P3306 -p