Which one is better?

rushenas · #1 (**permalink**) 01-08-06, 04:30

Hi all
I wanna know, which one of the following code is better (don't give a damn about the coding language, I just wanna know about SQL query):

Code1:

PHP Code:


			
$query = "SELECT * FROM products, categories, options WHERE products.product_id = '".$_REQUEST["id"]."' AND categories.prod_id = products.product_id AND options.category_id = categories.category_id";

$result = mysql_query($query);



for ($i=0; $i<mysql_num_rows($result); $i++)

{

     $record = mysql_fetch_array($result);

     // Showing results ...

}

Code 2:

PHP Code:


			
$query = "SELECT * FROM products WHERE products.product_id = '".$_REQUEST["id"]."'";

$result = mysql_query($query);



$record = mysql_fetch_array($result);

// Showing some results ...



$query = "SELECT * FROM categories WHERE categories.product_id = '".$_REQUEST["id"]."'";

$result = mysql_query($query);

for ($i=0; $i<mysql_num_rows($result); $i++)

{

     $record = mysql_fetch_array($result);

     $category = $record["category_id"]; 



     $query = "SELECT * FROM options WHERE options.category_id = '$category'";

     $result2 = mysql_query($query);

     for ($j=0; $j<mysql_num_rows($result2); $j++)

     {

          $row = mysql_fetch_array($result2);

          // Show results ...

     }

}

This is just a sample, of course I must have similar code for 5 tables (here is only 3 tables). So the first code will contain a more complicated query. But the second one contains more query. Which one is faster, and has better coding?

Maybe useful, products has some fields, including product_id. categories includes both product_id and category_id, and options contains option_id and category_id.