mysql select question

[Guest]

My question is, in the code below, what do the letters before the column names stand for?

 

"ap" "cc" "pp" "pr" Are these letters necessary? What is their purpose?

Is there any reference material explaining this?

 

 

	global $ddd;
$query="select ap.auctions_max as bid_price , ap.auctions_high_cust as customers_id,ap.auctions_id, ap.products_id, pp.products_name, pr.products_model, cc.customers_firstname, cc.customers_lastname, cc.customers_email_address, ap.notified, ap.status from ".TABLE_AUCTIONS_PRODUCTS." ap, ".TABLE_CUSTOMERS." cc, ".TABLE_PRODUCTS_DESCRIPTION." pp, ".TABLE_PRODUCTS." pr where ap.auctions_high_cust = cc.customers_id and ap.products_id = pp.products_id and ap.products_id = pr.products_id and ap.notified = 1 and ap.expires_date <'". date("Y-m-d").' '.date("G:i:s")."'  GROUP BY auctions_id";
$result=mysql_query($query);

 

Thanks, Gerald

[♥kymation]

They are shorthand for the table names. You could write them out in full as well: auctions_products.auctions_max, etc. The authoritative reference is the MySQL Manual, but it's not the easiest to find things in.

 

Regards

Jim

[♥geoffreywalton]

Try www.w3schools.com for an easy intro to mysql