Mysql 在多个表上联接
我有两个SQL表:Mysql 在多个表上联接,mysql,sql,Mysql,Sql,我有两个SQL表: select * from operation; id | name ----+-------------------- 1 | Account add 2 | Account edit select * from role_operation; id | role | operation ----+----------+----------- 1 | admin | 1 2 | operator | 1
select * from operation;
id | name
----+--------------------
1 | Account add
2 | Account edit
select * from role_operation;
id | role | operation
----+----------+-----------
1 | admin | 1
2 | operator | 1
3 | admin | 2
操作表中的id
列与角色操作中的operation
列链接。(外键)。如何获取操作name=Account add
我尝试了从role\u operation中选择role\u operation.role,operation.name对role\u operation进行内部连接操作。operation=operation.id代码>
但这将提供在角色操作表的操作字段中存在操作id的所有行。使用where
SELECT role_operation.role, operation.name
FROM role_operation
INNER JOIN operation ON role_operation.operation=operation.id
where operation.name = 'Account add';
在哪里使用
SELECT role_operation.role, operation.name
FROM role_operation
INNER JOIN operation ON role_operation.operation=operation.id
where operation.name = 'Account add';
您忘记了WHERE子句您忘记了WHERE子句请添加一些文字解释您的解决方案如何/为什么工作。请添加一些文字解释您的解决方案如何/为什么工作。