subtract a num from table

**insanemonkey** · 12-11-2007, 10:37 PM

ok I am making a delete page for my forum and i got everything completed, it works fine and everything but this is my code..

Code:

include "connect.php";

$delnum = $number;

mysql_query("DELETE FROM forum WHERE postid='$delnum'") 
or die(mysql_error());

but i use this for my forum and i have a seperate table called replies and it adds +1 everytime there is a reply but i want to know how i can make is subtract one everytime i delete a reply that it will subtract one

I dont know if this would be under php or mysql, sorry if i was wrong.

example:
10 replies delete one goes to 9 replies. but i delete one it still says 10 replies but there is only 9

**boogyman** · 12-12-2007, 02:03 PM

provided you assigned $number correction to $delnum try

PHP Code:


$delnum = $number;

mysql_query("DELETE FROM forum WHERE postid='". $delnum. "'") or die(mysql_error());

and if you want to find out if it worked you can do.

PHP Code:


if( mysql_query("DELETE FROM forum WHERE postid='". $delnum. "'") )
{
      echo mysql_query("SELECT COUNT(postid) FROM forum");
}

**insanemonkey** · 12-15-2007, 10:51 AM

ok heres a code i am trying to figure out,, its a modified version.

Hi everyone, I can seem to figure this out and why its not working, please help.

what I am trying to do is make a delete page for my forum which will delete the post id then i want it to update the parentid and to subtract 1 from number of replies.. heres what I am trying to do..

the delete button a post would look like this..
forums/delete.php?delnum=105&id=104

Code:

<html> 
<head> 

</head> 

<body onLoad="history.go(-1)"> 
<body bgcolor="#000000"> 

</body> 

</html> 

<?php 
  
$delnum = $delnum; //post number 
$sid = - 1; //subtract 1 from parentid or replies 
$id = $id; 
 ?> 

<?php 
include "connect.php"; 


mysql_query("DELETE FROM forum WHERE postid='$delnum'")  
or die(mysql_error());  //delete the post 


mysql_query("UPDATE forum SET numreplies='$sid' WHERE postid='$id'")  
or die(mysql_error()); //update number of replies by -1 where post id is 

?>

please help me out...
after it completes i want it to go back a page... thats why I have onload in there..
this wont even delete the post.. please help

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