Question

我正在尝试从我的一个表中选择用户数据行。我只想要在数组中有primary_key（user_id）的行。我怎么能这样做？

查询创建数组：

$suggestions_query= "
SELECT * 
  FROM relations 
 WHERE user1= '$user_id' 
   AND status = 1;
";
$suggestions_array= mysqli_query($connect, $suggestions_query);

查询以获取用户数据：

$search_query= "
SELECT * 
  FROM users 
 WHERE fname LIKE '%".$fname."%' 
   AND lname LIKE '%".$lname."%'" 
   AND IN ARRAY <!-- Code in Question

$search_result= mysqli_query($connect, $search_query)

Answer 1

尝试在1个查询中完成所有操作

SELECT * FROM users 
WHERE fname LIKE '%".$fname."%' 
AND lname LIKE '%".$lname."%' 
AND user_id IN (
               SELECT user_id FROM relations
               WHERE user1= '".$user_id."' 
               AND status= 1)

Answer 2

如果我正确理解了这个问题，听起来你想要使用内连接。你可以在这里阅读它们.. http://www.w3schools.com/sql/sql_join.asp

语法类似于..

"SELECT * FROM relations "
. "INNER JOIN users ON relations.user_id=users.user_id "
. "WHERE fname LIKE '%".$fname."%' AND lname LIKE '%".$lname."%' "
. "AND user1= '".$user_id."' AND status= 1"

这两个表必须具有user_id的并行值，即，您将user_id视为外键。

希望这有帮助

Answer 3

您可以使用子查询。

您可以将两个查询组合成以下内容：

$search_query= "SELECT * FROM users WHERE fname LIKE '%".$fname."%' AND lname LIKE 
'%".$lname."%'" AND id in (SELECT id FROM relations where user1= '".$user_id."' AND status= 1)"

Answer 4

SELECT * FROM users WHERE fname LIKE '%".$fname."%' AND lname LIKE 
'%".$lname."%'" AND user_id IN (SELECT user_id FROM relations WHERE user1= '".$user_id."' AND STATUS= 1)

结合MySQL查询

4 个答案: