Question

我有以下表格：

USERS:                               ITEMS

user_id  name    always_show         id   user_id  name
--------------------------           --------------------------------
1        Joe                         1    1        Apple   
2        Sam                         2    1        Banana
3        Walter  1                   3    2        Cherry

我在做这个查询：

SELECT * FROM
  users Inner Join
  items On users.user_id = items.user_id

问题是：我如何添加所有其他具有标记always_show设置的用户？

Answer 1

我希望我理解你的问题:-)试试UNION

SELECT u.* FROM users u
INNER JOIN items i ON u.user_id = i.user_id

UNION ALL SELECT * FROM users WHERE always_show = 1

Answer 2

SELECT * 
FROM users 
INNER JOIN items On users.user_id = items.user_id
UNION
SELECT * 
FROM users 
LEFT OUTER JOIN items On users.user_id = items.user_id AND users.always_show = 1

Answer 3

SELECT * FROM
  users Inner Join
  items On users.user_id = items.user_id where Users.always_set = 1

MySQL查询 - 有点棘手

3 个答案: