MySQL查询错误

Question

有人可以帮我纠正我试图运行我的MySQL查询时得到的以下错误。

这是我的错误。

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE user_id = '3' AND id = '3' AND friendship_status = '0'' at line 2 

这是我的mysql代码。

SELECT users_friends.* 
WHERE user_id = '$user_id' 
AND id = '$request_id' 
AND friendship_status = '0' 

Answer 1

大概需要添加：FROM users_friends只是WHERE之前。

SELECT users_friends.* 
FROM users_friends 
WHERE user_id = '$user_id' 
AND  id = '$request_id' 
AND  friendship_status = '0' 

Answer 2

试试这个

（PHP假定）

$string = "SELECT from database_name.table_name 
      WHERE user_id ='".$user_id."' AND id= '".$request_id."' 
      AND friendship status ='0' "; 

我假设$user_id和$request_id是varchar/text类型的