Populating a third form from a db

JakesSA

Here's the thing... in my DB I have 3 tables, called YEAR, MONTH and DAY. In my day table there are only 4 to 5 days that correspond to a month and year.
If a user selects a year and month from two drop down menus, how do I populate a third form (dropdown) with the corresponding days to that particular month and year.

I'm using PHP 4.2 and mysql as the db... so if anyone can please help or knows where there is a article on the net explaining this, I will appreciate it.

barand

After the user has selected the year and month you'll have to submit the form (action="$PHP_SELF" or another similar form) to pass the year and month variables to your script. A javascript 'onchange' event handler on the MONTH select component can do this .

Assuming your day table contains year and month keys, select the days you want and build the select options list for DAY.

hth

JakesSA

great...now how does that work?

Toby

Show us what you got so far...

How exactly do the tables and the form look?

kamy99

The form doesn't need to be submitted!

If you populate all the dropdowns from the DB, you can create the javascript file dynamically too.

barand

To Kamy99

You can not populate third until you have the selections from the other two. If the DB is on the server how would you do it without resubmitting?

kamy99

if the tables are linked properly you can populate them any which way you want!

Basically you through your query result in an array, populate js, then onchange the third options gets populated.

aldur

If your data size is small you can use javascript holding all information in an array but if you expect the size of the tables to get massive you need to resubmit. Note that the size of your table will be the amount of information that a web page user will have to download before they see the page. and you normally only have 7 seconds before people get bored and move off to another location.

use a multideminsional array to hold your information you can then use onchange in the select boxes of the first two pull downs to generate the options of the third.

document.myform.myopt3.options.length=0;

for each element to display
document.myform.myopt3.options[document.myform.myopt3.options.length] = new option (value,text);
next

barand

Thanks, Aldur

document.myform.myopt3.options.length=0; 

for each element to display 
document.myform.myopt3.options[document.myform.myopt3.options.length] = new option (value,text); 
next

I've used a similar technique in php to download and hold lookup data (prices) for use by a js function but I didn't know the incantations to populate the options of a select list.