Using JavaScript to get DB data

ihugo

Hi,

my database holds names and email addresses. My php frontend displays a page where the names can be selected and a text input field for email addresses. The database is not complete, so there are many names without email data.

What I'm trying to do is to automatically lookup the database for an existing email address in case a name has been chosen.

Therefore I added an onFocus event to the input field to execute some javascript. Inside this script I want to perform some database stuff to retrieve the corresponding email address for the chosen name. For this to work I need to pass the name-value from js to php.

Everything I tried doesn't work and even internet search engines did not find anything. Does anyone got an idea how to solve this problem?

thanks and best regards
Hugo

sarahk

You'll have to do a PHP hit on the database, but you can initiate that using javascript and hidden iframes.

Take a look at http://www.hostultra.com/~data/muck/example.php

the source is all there, I'm just not using a database.

Sarah

ihugo

Hi Sarah,

thanks for your reply. I checked out your page and the iframe concept.
It's not what I need to have. My Problem is that I can't pass a variable in javascript like
myJsVar = Document.myForm.myInputField.value();
to php like

$myPhpVar = myJsVar

I need this var for the database request...

best regards
Hugo

sarahk

No probs Hugo

How are you planning to initiate the reload of your page.

Common techniques:
user submits a form (use javascript to populate a hidden variable on the form, that variable is then a php variable)
clicks a hyperlink (which might also submit a form) and might set the window.location = newurl + "?id=" + myVar, which then passes myVar down to the server and it becomes a PHP variable

Let me know you technique and we'll get it sorted.

Sarah

ihugo

The desired action should take place before the form is submitted. When a user selects a name from the select box, I want to perform a database query to autofill the email input field. If an email address is available, it should appear in the appropriate input field.
The form submit comes later...

best regards
Hugo

leatherback

Hi Ihugo,

You CANNOT get the data from your database, without SUBMITTING data to the database. Keep in mind that PhP runs on the server, and your javascript runs on the clients machine: Data has to be submitted between the two of them. Unless you decide to download all theinfo from the database into a javascript array, which you use to poulate your fields. (Keep in mind that this will lead to a lot of datadownloading when yourdatabase is large!)

The suggestions given before might work, but beware: More and more people are switching off javascript in their browsers, which will cause these scripts to malfunction.

Yours,

Jelle.

sarahk

without knowing your target market the switching off javascript thing will be more of a problem.

Because the data is sensitive you don't want to preload all the options into a "javascript" array which would be the other option.

The example I give is without submitting, the user selects something, the javascript event submits a hidden form and returns the data. The user hasn't submitted the main form.

the only other way is to break your form into "pages" where the user clicks "next"