Hi I have a MySQL database table "points" the user can click a button and a point should be removed from their account, the button they pressed has an ID of another user, therefore their account must increase by one.
I have it working in jQuery and checked the varibles/posts in Firebug, and it does send the correct data, such as:
userid= 1
posterid = 4
I think the problem is with my PHP page:
<?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;
}
}
?>
Any ideas? Thanks :)
Two queries to increase/decrease field value are not necessary:
mysql_query("UPDATE table SET field = field + 1 WHERE id = $number");
is a perfectly valid query as you can see next:
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)
Having that tested, are you sure you get into your if (loggedin())
clause?
I have to agree with KM
, would be nice to see output of echo $query1;
or echo $query2;
以下是我测试的示例查询,它正在100%工作
$query="UPDATE table_name SET `hit_count`=(`hit_count`+1) WHERE `id` = '1'";
update table_name set col_name=col_name+1 where sqId = 12
但是,如果您的col_name
默认值为null或为空,则它永远不会起作用,因此请确保col_name
默认值为0
或任何整数值。
try adding in something to print out your actual SQL command, before the if ($result1 && result2)
:
ECHO '$query1='.$query1.'<br>';
ECHO '$query2='.$query2.'<br>';
this will help to see what it is sending to the database
update 'tablename' set 'columnname1'='columnname1' + 1 where 'columnname2'='value';
eg: update students set englishmarks=englishmarks + 1 where name='Rahul';
Edit:(Explanation) "UPDATE" keyword is used to update a vaule in the table. Here I am updating a value in the table "students". "SET" keyword updating the english marks by 1(just like in C language, how we increase the value of an integer, i=i+1) and condidtion is given where name is "Rahul".
So englishmarks of Rahul are incremented by 1
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