Question

I have a MySQL table called “invoice_prod” :

id | qte | price | id_tva 

And another table called “tva” :

id_tva | content

Now, I want to find the total of an invoice, so I made this query and it works.

$sql_mnt = mysql_query("
    SELECT SUM( (qte * price) * ( 1 + (tva / 100))) AS total_un_prod
    FROM invoice_prod 
    WHERE id='$id_invoice'
    ");

I have just one problem with this query. The “tva” return the “id of the tva” and not its content. Which I have to extract its content from the table “tva”.

Clearly, this query return this value of the tva : “1”, or, it should return “18%” which is the content of the tva’s ID.

I tried to make a PHP function that extracts the tva’s content from an id and include it into the SQL query like this :

$sql_mnt = mysql_query("
    SELECT SUM(( qte * price) * ( 1 + (" .
    tva_get_by_id(tva) . "/ 100))) AS total_un_prod
    FROM invoice_prod 
    WHRE id='$id_invoice'
    ");

But it doesn’t work.

What should I do ?

Thanks a lot for your help and have a nice day 🙂

Answer 1

use

$sql_mnt = mysql_query("
         SELECT SUM((`qte`*`price`)*(1+(`content`/100))) AS `total_un_prod`
         FROM `invoice_prod`
         LEFT JOIN `tva` USING (`id_tva`)
         WHERE `id`='".mysql_real_escape_string($id_invoice)."'");

this connects the two tables within mysql, so you can use the content field directly, which I presume holds the TVA percentage.

edit formatted and addressed the escaping of id_invoice as well (I guess it is int so a cast would suffice, but if not, this will work as well)