accessing server database within javascript form

[Navodit]

I have 3 dropdowns in my application. Based on the selections made in the
first two dropdowns, I need to pull out data from the database to set up the
corresponding menu for the third dropdown. How can I connect to the database
on the server after the first two dropdowns have been selected by the user
in order to be able to set up the third dropdown?

The first dropdown is states (8 in number for my application). The second is
counties (approx 80+ for each state). The data for the second dropdown is
calculated based on choice of the first dropdown. However since there are
only 8 states, i retrieve the data for 8 states and store it in arrays which
are then used for populating the second dropdown.

The problem is that now for the third dropdown there can be a very large
number of possible combinations of state and county. Retrieving this data
from the database beforehand might be overkill. I am looking at a dynamic
way to be able to retrieve this data on the fly. Is this possible at all?
Any hints/ideas would be appreciated...

[Randy Webb]

Navodit said the following on 4/24/2007 11:13 AM:

I have 3 dropdowns in my application. Based on the selections made in the
first two dropdowns, I need to pull out data from the database to set up the
corresponding menu for the third dropdown. How can I connect to the database
on the server after the first two dropdowns have been selected by the user
in order to be able to set up the third dropdown?

http://jibbering.com/faq/index.html#FAQ4_34
http://jibbering.com/faq/index.html#FAQ4_44

Although personally, I would load the new data in a .js file by
dynamically inserting a script element in the page. Get my data back as
JSON Data and off to the races.
--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[Navodit]

"Randy Webb" <Hi************@aol.comwrote in message
news:AK********************@giganews.com...

Navodit said the following on 4/24/2007 11:13 AM:

>I have 3 dropdowns in my application. Based on the selections made in the
first two dropdowns, I need to pull out data from the database to set up
the corresponding menu for the third dropdown. How can I connect to the
database on the server after the first two dropdowns have been selected
by the user in order to be able to set up the third dropdown?

http://jibbering.com/faq/index.html#FAQ4_34
http://jibbering.com/faq/index.html#FAQ4_44

Although personally, I would load the new data in a .js file by
dynamically inserting a script element in the page. Get my data back as
JSON Data and off to the races.
--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices -
http://www.JavascriptToolbox.com/bestpractices/

I am new to Javascript and am not quite sure how to use ajax here. Should I
create a xmlhttprequest object which invokes a .asp file which in turn
queries the database. And then retrieve the data from the xmlhttprequest
object? Would there be any sample scripts available which might give me some
idea how to code such a script? Any help would be appreciated. thanks..

[Randy Webb]

Navodit said the following on 4/25/2007 4:48 PM:

"Randy Webb" <Hi************@aol.comwrote in message
news:AK********************@giganews.com...

>Navodit said the following on 4/24/2007 11:13 AM:

>>I have 3 dropdowns in my application. Based on the selections made in the
first two dropdowns, I need to pull out data from the database to set up
the corresponding menu for the third dropdown. How can I connect to the
database on the server after the first two dropdowns have been selected
by the user in order to be able to set up the third dropdown?

http://jibbering.com/faq/index.html#FAQ4_34
http://jibbering.com/faq/index.html#FAQ4_44

Although personally, I would load the new data in a .js file by
dynamically inserting a script element in the page. Get my data back as
JSON Data and off to the races.

I am new to Javascript and am not quite sure how to use ajax here. Should I
create a xmlhttprequest object which invokes a .asp file which in turn
queries the database. And then retrieve the data from the xmlhttprequest
object?

Yes, that is how you would do it.

Would there be any sample scripts available which might give me some
idea how to code such a script? Any help would be appreciated. thanks..

<URL: http://www.ajaxtoolbox.comwould be about the best place to
start. Ready made library that is pretty simple to figure out.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/

[kday]

Yup, it's called AJAX. It uses the javascript xmlHttpRequest object
to pull data from the server after the page has loaded. It's used all
over the web, most notably with Gmail.

Here's one example that I quickly found on a PHP forum:
http://www.webmasterworld.com/php/3308690.htm

but there are literally thousands of examples on the web:
http://www.google.com/search?q=ajax

[Randy Webb]

kday said the following on 4/25/2007 6:38 PM:

Yup, it's called AJAX.

"Yup"? But, it is called "Quoting what you are replying to".

It uses the javascript xmlHttpRequest object
to pull data from the server after the page has loaded. It's used all
over the web, most notably with Gmail.

Somehow, I doubt Hmail is the "most notable" use of AJAX.

--
Randy
Chance Favors The Prepared Mind
comp.lang.javascript FAQ - http://jibbering.com/faq/index.html
Javascript Best Practices - http://www.JavascriptToolbox.com/bestpractices/