Walkthrough Two - Build your own PHP Survey/Poll Application

Hi Mac,

My question is about the primary/foreign key passed between the two tables, i.e.: 'tblquestions' and 'answers' in this section.

In tablquestions it is quite clear how question 4 is pulled from the table,i.e. include 'sqlSurvey.php';.

However in the answers table we are SET-ting a column A,B or C. So my question is how does mysql know which row in the answers table needs to be incremented by 1if we only indicate a column? How is the QID passed to the answers table? I just don't see it.

Thanks
Ian

of all the 13 chapters and the 3 walkthroughs this topic i had to revisit, in light of 77928490 concern i am also finding myself wondering in some coding suspenses. Not sure if i
exactly understand the question being asked but from the database point of view the QID in tbquestions has qa, qb and qc, if u notice QID in the answers tables also has QID with respectives
3 answers, the link should should be there. I think the sql query

Language: PHP
<?php
$qnum =';4';;
$sql = "select * FROM tblquestions.QID = ';$qNum';;
?>

is how it shoud get pulled but thats just for question 4 only as you suggested, not yet fully confident with all the codings but i think thats a start, not sure what the others think

..&ru..

Really enjoyed coding for graph, simple but effective, good to know that logic can produce colour! Find these walkthroughs very helpful.

77928490 Wrote:
-------------------------------------------------------
> Hi Mac,
>
> My question is about the primary/foreign key
> passed between the two tables, i.e.:
> 'tblquestions' and 'answers' in this section.
>
> In tablquestions it is quite clear how question 4
> is pulled from the table,i.e. include
> 'sqlSurvey.php';.
>
It can be confusing (and is).... best way is to run it all as opposed to just reading through it (not saying that is what you are doing).

Add the Vote to the Database page explains it, although they acknowledge that they are taking shortcuts

Language: PHP
$selected_radio = $_GET[';q';];
// This just gets which radio button was clicked. The value comes from the HTML form, and will be A, B or C. This is then placed into the variable called $selected_radio.
// $selected_radio will then have the value A or B or C
 
$SQL = "UPDATE answers SET $selected_radio = $selected_radio + 1";
 
//e.g. SET $selected_radio =.... is now SET A =.....
 $SQL = "UPDATE answers SET  A = $selected_radio + 1";