Fetch data from database with PHP and AJAX

[seblil]

First off, thanks for letting me into the forums.

Excuse a newbie but I have a question about fetching data from a database with PHP and AJAX.

Let's say I wanted to fetch data from the database like in this example from W3Schools, but I had modified the dropdown to for example fetch all entries with last name Griffin, Swanson or Quagmire. I made the q variable take a string instead of an integer.

$q = strval($_GET['q']);

Now I want to expand the SQL query to also take another condition.

"SELECT * FROM user WHERE LastName = '".$q."' AND Hometown = '".$q2."'";

I understand how to build the query and that I need to declare another variable (q2), but how do I modify the AJAX request?

xmlhttp.open("GET","getuser.php?q="+str,true);

 Also, would I need to have a submit button now that there are two conditions?

Thanks!

[dsonesuk]

IF you are talking about multiple selection dropdown the value would contain 'Griffin,Swanson,Quagmire', so you would not need to change JavaScript, only the php side to split those names from $_GET['q']

For passing second variable, you have to run a function to retrieve the two values and apply to variables 'str' sames as before, and lets say 'home', then in ajax querystring

xmlhttp.open("GET","getuser.php?q="+str+"&hometown="+home,true);

Then in php

$homeTown = strval($_GET['hometown']);

 

[justsomeguy]

If you're sending string values in the URL then you'll also want to use the encodeURIComponent function to make sure the values don't break the URL.  Otherwise, if you're sending a lot of data you'll probably want to just switch to a post request instead of a get request.