Question

我有3个值：

的ObjectID
用户电子邮件
用户密码

两张桌子：

对象：
- object id
- 用户ID
- 对象名称
用户：
- 用户ID
- 电子邮件
- 密码

我想在以下情况下选择对象的名称：

用户有效（电子邮件并传递返回行）
和对象属于用户或具有用户id = 0（属于所有人）
object.id = ObjectID

什么sql语句可以帮到我？

Answer 1

未经测试但应该有效。

SELECT 
    o.object_name 

FROM
    objects o
    LEFT JOIN users u ON o.user_id = u.user_id

WHERE
    o.objectId = 1
    AND (
        (u.email = ''
        AND u.password = '')
        OR o.user_id = 0
    )

Answer 2

只返回对象名称？

SELECT object_name 
FROM objects o LEFT JOIN users u ON o.user_id = u.user_id
WHERE (u.email IS NOT NULL
AND u.password IS NOT NULL) 
OR user_id = 0

Answer 3

SELECT o.object_name FROM objects o
LEFT JOIN users u ON o.user_id=u.user_id
WHERE (u.email IS NOT NULL AND u.password IS NOT NULL)
OR o.user_id=0

我不确定你的意思是object_name还是object_id？

Answer 4

SELECT 
   o.Name
FROM
   Objects o
LEFT JOIN
   Users u
ON
   u.Id = o.UserId
WHERE
   (u.Email = email
AND
   u.Password = password)
OR
   o.UserId = 0

Answer 5

如果你想测试，我把对象放在SqlFiddle中。

http://sqlfiddle.com/#!2/86023/9

SELECT O.ID FROM OBJECTS O

 WHERE O.ID IN  (
SELECT U.ID FROM USERS U
WHERE  U.USER = 'test' AND U.PASS = 'test'
)

OR O.USERID = 0

如果条件适用，则选择SQL

5 个答案: