在MySQL中将行值增加和减少1

Question

嗨我有一个MySQL数据库表"点"用户可以点击一个按钮,一个点应该从他们的帐户中删除,他们按下的按钮有另一个用户的ID,因此他们的帐户必须增加一个.

我让它在jQuery中工作并检查Firebug中的varibles/posts,它确实发送了正确的数据,例如:

userid= 1 
posterid = 4

我认为问题出在我的PHP页面上:

<?php


include ('../functions.php');

$userid=mysql_real_escape_string($_POST['user_id']);
$posterid=mysql_real_escape_string($_POST['poster_id']);

if (loggedin()) 
{
include ('../connection.php');
$query1 = "UPDATE `points` SET `points` = `points` - 1 WHERE `userID` = '$userid'";
$result1=mysql_query($query1);


$query2 = "UPDATE `points` SET `points` = `points` + 1 WHERE `userID` = '$posterid'";
$result2=mysql_query($query2);


if ($result1 && result2)
{
    echo "Successful";  
    return 1;
}
else
{

    echo mysql_error();
    return 0;   
}
}
?>

有任何想法吗？谢谢 :)

Answer 1

增加/减少字段值的两个查询不是必需的:

mysql_query("UPDATE table SET field = field + 1 WHERE id = $number");

是一个完全有效的查询,你可以看到下一个:

mysql> describe points;
+--------+---------+------+-----+---------+-------+
| Field  | Type    | Null | Key | Default | Extra |
+--------+---------+------+-----+---------+-------+
| uid    | int(11) | NO   | PRI | NULL    |       |
| points | int(11) | YES  |     | 0       |       |
+--------+---------+------+-----+---------+-------+
2 rows in set (0.05 sec)

mysql> insert into points VALUES (1,0),(2,0);
Query OK, 2 rows affected (0.14 sec)

mysql> select * from points;
+-----+--------+
| uid | points |
+-----+--------+
|   1 |      0 |
|   2 |      0 |
+-----+--------+
2 rows in set (0.05 sec)

mysql> update points set points = points+1 where uid = 1;
Query OK, 1 row affected (0.27 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from points;
+-----+--------+
| uid | points |
+-----+--------+
|   1 |      1 |
|   2 |      0 |
+-----+--------+
2 rows in set (0.00 sec)

经过测试,你确定你会进入你的if (loggedin())条款吗？

我必须同意KM,很高兴看到echo $query1;或的输出echo $query2;

Answer 2

以下是我测试的示例查询,它正在100%工作

$query="UPDATE table_name SET `hit_count`=(`hit_count`+1) WHERE `id` = '1'";