Different Types of Database Call

[melina386 10]

I'm trying to help a friend debug a shopping cart system, and am confused by several different types of database call occurring on the same page. Can some kind soul explain what the material differences are between these calls, and why you'd use them?

 

 

Firstly, the "normal" (or so I thought, anyway) query pattern:

 

$sql_insert_order = "insert into order_tbl set ".

" order_number = '$order_no'".

etc etc etc etc

" ,shipping_zip = '$postcode_d'";

 

$sql_insert_order_qry = mysql_query($sql_insert_order) or die(mysql_error());

 

 

i.e. write the query, then run it.

 

- - - -

 

But then elsewhere on the page I find:

 

$sql_update_customer = mysql_query("update buyer_tbl set ".

" buyer_sname = '$name_d'".

etc etc etc

" ,shipping_phone = '$phone_d'".

" where visit_session = '$session'");

 

$result = mysql_query($sql_update_customer);

 

 

which seems to run the query twice?

 

- - - -

 

 

But then, to really mess with my head, I then also find:

 

 

echo $sql_add_customer = mysql_query("insert into buyer_tbl set ".

" visit_session = '$session'".

" ,buyer_sname = '$name_d'".

etc etc etc etc

" ,shipping_zip = '$postcode_d'");

 

$result = mysql_query($sql_add_customer);

 

 

Which completely baffles me - again, a sort of double query, but why the echo?

 

 

Any words of wisdom on why these three different methods are going on, would be very much appreciated!

 

(I'm well aware that it's normal syntax to use 'values' rather than 'set' in an insert query - I was rather surprised to see this. But let's leave that one aside for now!):helloooo: