mysql query using php to pull from multiple tables

kroleig1

I am having trouble simplifying my mysql query.

I have 3 tables I need to verify data in before I add new data to it.

The code is as follows:
(this takes place after all validation of form data has been completed.)

if (empty($errors)) { //If all is ok. Data caused no errors

//Test for unique records. Product name and url and prod type and price
$query1 = "SELECT id FROM products WHERE prod_name='$prod_name' AND url=$url";
$result1 = mysql_query($query1);

	$query2 = "SELECT id FROM sizes WHERE size=$size";
	$result2 = mysql_query($query2);

			$query3 = "SELECT id FROM prod_type WHERE prod_type=$type_of";
			$result3 = mysql_query($query3);

$row_result1 = mysql_num_rows($result1);
$row_result2 = mysql_num_rows($result2);
$row_result3 = mysql_num_rows($result3);

//This means key entries are identical. Prevent user from entering duplicate data
if ( ($row_result1 && $row_result2 && $row_result3) == 1) {
$errors[] = 'You may have entered this item before, please check your data again.';
} else {
//Run the query

The tables I want to pull from are:
products, prod_type and sizes

Is there a way i can use joins to minimize my queries?

I appreciate all your help.

Thank you kindly in advance.
-r