Basic If Statement Help

StevenF · 02-26-2008, 11:52 PM

Hi guys,

I have what I think is a very basic question: I have a form which inserts data into a database. When the form is submitted (when mysql_query($query) = true) I want to echo "A new row has been added".

Here's the code:

PHP Code:


			
//Creating a query that enters the data into a database

    $query = 'INSERT INTO products SET    cd_artist = "'.mysql_real_escape_string($cd_artist).'",

                                        cd_title = "'.mysql_real_escape_string($cd_title).'",

                                        cd_price = "'.mysql_real_escape_string($cd_price).'",

                                        cd_image_name = "'.mysql_real_escape_string($cd_image_name).'"';

    

    //execcute a query on a MySQL database

    mysql_query($query);

    

    //Message

    if (mysql_query($query) == 1 ) {

        echo ("A new row has been added to the database");



    }

I also tried:

PHP Code:


			
//Message

    if (mysql_query($query)) {

        echo ("A new row has been added to the database");



    }

No luck. I know this is something very basic, but I can't get it to work

Thanks,
Steven

TlcAndres · 02-26-2008, 11:53 PM

I believe mysql_affected_rows() is what you're looking for, look it up on php.net

xenon · 02-27-2008, 12:01 AM

mysql_query returns a resource on success, and false in case of a failure. It doesn't return 1 in any circumstance. Also, watch out. You're executing the same query twice:

Code:

//execcute a query on a MySQL database 
    mysql_query($query); // first time
     
    //Message 
    if (mysql_query($query) == 1 ) { // and here you go again

, the result being 2 identical rows inserted into the database.

StevenF · 02-27-2008, 12:03 AM

Quote:

Originally Posted by TlcAndres

I believe mysql_affected_rows() is what you're looking for, look it up on php.net

I don't think that is what I'm looking for.

Quote:

Originally Posted by xenon

mysql_query returns a resource on success, and false in case of a failure. It doesn't return 1 in any circumstance.

Oh OK. I wasn't sure how it worked, so I thought I would try 1 = true and 0 = false but that didn't work. Do I have the right idea on the second example?

EDIT: Just seen you've added a little to your post. I see... so I'm executing the query twice and inserting the same row twice, DOH!. How else can I check that the query has been executed?

Wildhoney · 02-27-2008, 12:04 AM

As Andres rightfully pointed out:

php Code:

if(mysql_affected_rows() > 0)
{
    echo ("A new row has been added to the database");
}

StevenF · 02-27-2008, 12:12 AM

Quote:

Originally Posted by Wildhoney

As Andres rightfully pointed out:

php Code:

if(mysql_affected_rows() > 0)
{
    echo ("A new row has been added to the database");
}

When I try that, it echos' "A new row has been added to the database" weather the form has been submitted or not.

Wildhoney · 02-27-2008, 12:35 AM

It works from the mysql_query function call. If the mysql_query function call is not false, then mysql_affected_rows will return an integer of how many rows have been affected. If you inserted one row into the database successfully, then the integer 1 would be returned.

StevenF · 02-27-2008, 12:46 AM

I think I get how it works now:

mysql_affected_rows() checks that mysql_query($query) has been executed. If it has, then the value for mysql_affected_rows() becomes 1. Therefore (mysql_affected_rows() is going to be greater than 0 and should echo "You have inserted a new row into the database".

But for some reason it is echoing before the submit button is presses (value should be 0).

maZtah · 02-27-2008, 10:21 AM

You could also do:

PHP Code:


			
mysql_query($szQuery) or die(mysql_error());

echo 'Query succesful';

If the query fails it will die with echoing the mysql error, if it succeeds it will echo the message.

StevenF · 02-27-2008, 11:43 AM

Oh I know what's happening! My PHP and MySQL code is on the same page as the form. So when the page loads, the query is automatically being exexuted and adding blank data into the database, hence why it's always echoing "You have successfully added a new row". I put it all on the one page to keep everything neat and to cut down on pages. I can see now that I will have to have a seperate page for the PHP and MySQL code.

freenity · 02-27-2008, 12:25 PM

or just add:

PHP Code:


			
if (!isset($_POST['submit']))
{
//show form
}
else
{
//insert
}

and you will need to name your submit button as submit:

<input type="submit" name="submit">

StevenF · 02-27-2008, 12:52 PM

Thanks Freenity, that really helped! I done something very similar:

PHP Code:


			
if (isset($_POST['submit']))

{

//execute query 

echo ("A new row has been added to the database");

}

Thanks for pointing out the isset function to me, it will prove to be very useful!

maZtah · 02-27-2008, 11:55 PM

Another option would be:

PHP Code:


			
if ($_POST)

{

    // query shizzle

}

Gareth · 02-28-2008, 08:49 AM

You could also do:

PHP Code:


			
$qQuery = mysql_query(" QUERY ") or die();



if ( $qQuery ){

echo 'inserted';

}{

echo 'not inserted';

}