MySQL查詢 - 有點棘手

Question

我遇到下面的表格：

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 

我做這個查詢：

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

的問題是：我怎樣才能添加其他用戶，其有標誌always_show設置？

Answer 1

我希望我明白你的問題:-)嘗試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