PHP AJAX Database

PHP AJAX Database


AJAX can be used for interactive communication with a database.

Example Explained - The MySQL Database

The database table we use in the example above looks like this:

id FirstName LastName Age Hometown Job
1 Peter Griffin 41 Quahog Brewery
2 Lois Griffin 40 Newport Piano Teacher
3 Joseph Swanson 39 Quahog Police Officer
4 Glenn Quagmire 41 Quahog Pilot

 

The PHP File

The page on the server called by the JavaScript above is a PHP file called "getuser.php".

The source code in "getuser.php" runs a query against a MySQL database, and returns the result in an HTML table:

Explanation: When the query is sent from the JavaScript to the PHP file, the following happens:
  1. PHP opens a connection to a MySQL server
  2. The correct person is found
  3. An HTML table is created, filled with data, and sent back to the "txtHint" placeholder
Example Explained

In the example above, when a user selects a person in the dropdown list above, a function called "showUser()" is executed.

The function is triggered by the onchange event.

Here is the HTML code:

output : screenshot of code looking this type when we click and submit input data shown in table form

And table is :

Code explanation:

First, check if person is selected. If no person is selected (str == ""), clear the content of txtHint and exit the function. If a person is selected, do the following:

  • Create an XMLHttpRequest object
  • Create the function to be executed when the server response is ready
  • Send the request off to a file on the server
  • Notice that a parameter (q) is added to the URL (with the content of the dropdown list)