No id tag redirect

ElaineB

Elaine n00b here again 🙂

First I want to thank the members of this board for their amazing help. I have learned a lot from everyone who has responded to my posts and I am slowly being able to build my website to be more functional. Since posting to this board a few weeks ago I have learned how to expand my database, join tables, do multiple queries and even do some relevant if statements. Thanks everyone for their patience and generosity.

Now ... my latest question which I thought I knew the answer to but I've tried it with no luck ...

If I call up the url for an item in my database like:

http://www.domain.com/product.php?prod_id=1

I get the info for product 1 no problem. Now I only have about 60 products but lets say someone types in ..

http://www.domain.com/product.php?prod_id=61

I don't have a 61st product in my database but it still will show the template just with no information. I'd like to show a different kind of page if there is no product id. I have tried an if statement and I'm not having any luck because the prod_id isn't empty, it just doesn't exist. (i know how to display different info if the field is empty using an if statement)

How would I specify that i want to send the user to a different page if the prod_id doesn't exist?

Thank you very much in advance.

Elaine

vponz

Try something like this:
<?php
// Make some checks
...
...
...

if (!OK) //
header("location: whatever.php?");
else
// Continue with the page;
?>

Be sure you don´t send any HTML before you redirect to another page. If so, you will receive an error (Output already started...)

ElaineB

😕 😕 😕 😕

vponz

I think you didn´t understand anything! (Sorry)

<?php
// Check if the Id exists
$Sql = "Select * from table where id = $id";
// Run the query
if (the query returns no results)
header("location:whatever.php");
else
write the page;
?>

stolzyboy

<?
if ($_GET['prod_id'] == "")
{
echo "No product for that ID";
}
else
{
//do query to get info on that ID
}
?>

ElaineB

stolzyboy THANK YOU! WORKS PERFECTLY!

stolzyboy

<? 
if ($_GET['prod_id'] == "") 
{ 
echo "No product for that ID"; 
} 
else 
{ 
header("Location: pagetogo.php"); //redirects, but make sure there is NO output before this line or it will throw an error
} 
?>

bastien

elaine, i think you might want to combine vpoz and stolzyboy's code to make a true check

<?  

if ($_GET['prod_id'] == "")  //works only if product id is empty, not if larger than current db values
{  

echo "No product for that ID";  

}  

else  

{  

// Check if the Id exists 
$Sql = "Select max(id) from table"; 
// Run the query 
$result=mysql_query($Sql);

$id ==mysql_fetch_row($result);



if ($_GET['prod_id']>$id){   //the given prod_id is larger than the id from the db query
   echo ""No product for that ID";  
}else{
    header("Location: pagetogo.php"); //redirects, but make sure there is NO output before this line or it will throw an error 
}  

?> 

hth