Only possible to DELETE if there is no hits?

[developer]

Hello! 🙂

In this code, the thing is that it should only be possible to delete a "category" if there is no posts( "companies") with that category in it.

How can I please change the line: "if hits{" so it checks if there is any hits?

Thanks in advance.

$dbh=mysql_connect ("localhost", "ghost_user", "xxxxx") or die ('I cannot connect to the database because: ' . mysql_error());
mysql_select_db ("ghost_busdir"); 

$Query = "SELECT * FROM categories WHERE `id`=$id";
if hits{
	echo "You have to delete all companies first in this category to be able to delete the category!"

}else{

$Query = "DELETE FROM categories WHERE `id`=$id";
$Result = mysql_query($Query) or die("Error: ".mysql_error()." in query: ".$Query);
}

[Sxooter]

After query, you need to run the query:

$res = mysql_query($query);
if (mysql_num_rows($res)==0){
  // do not update
} else {
  // do update
}

[developer]

Hello!

Thanks for the answer 🙂

Actually it don't work yet, it deletes a catagory even if there are posts with that category.

The code now looks like this:

$Query = "SELECT * FROM categories WHERE `id`=$id";
$res = mysql_query($Query); 

if(mysql_num_rows($res)==0){ 
	echo "You have to delete all companies first in this category to be able to delete the category!";
}else{
	$Query = "DELETE FROM categories WHERE `id`=$id";
	$Result = mysql_query($Query) or die("Error: ".mysql_error()." in query: ".$Query);
	echo "The category is now deleted";
}

[saracen]

[QUOTE

$Query = "SELECT * FROM categories WHERE `id`=$id";
$res = mysql_query($Query); 

if(mysql_num_rows($res)==0){ 
	echo "You have to delete all companies first in this category to be able to delete the category!";
}else{
	$Query = "DELETE FROM categories WHERE `id`=$id";
	$Result = mysql_query($Query) or die("Error: ".mysql_error()." in query: ".$Query);
	echo "The category is now deleted";
}

[/B][/QUOTE]

It doesnt work because you have it the wrong way round. The line

if(mysql_num_rows($res)==0) is saying if there are 0 records in the database. In your code you are saying if there are 0 records bring up the echo else delete everything. You can change it either so that the if statement reads

if(mysql_num_rows($res)>0){

or swap the resulting code between the if and the else

[Sxooter]

Can't you just use innodb tables with cascading deletes for this?