AJAX database

PHP - AJAX and MySQL

AJAX can be used to communicate interactively with the database.

AJAX Database Example

The following example will demonstrate how a web page reads information from the database through AJAX:

Example

Select a person: Peter Griffin Lois Griffin Joseph Swanson Glenn Quagmire

Select the corresponding option, the user information will be displayed here...

Example explanation - MySQL database

In the above example, the database table we use is as follows:

Example explanation - HTML page

When the user selects in the drop-down list above When a user is selected, a function named "showUser()" will be executed. This function is triggered by the "onchange" event:

   
  
  Select a person: Peter Griffin Lois Griffin Glenn Quagmire Joseph Swanson  
 
 
Person info will be listed here.
  

showUser() function performs the following steps:

1) Check if a user is selected

2) Create an XMLHttpRequest object

3) Create a function that executes when the server response is ready

4) Send a request to a file on the server

5) Please note the parameters added to the end of the URL (q ) (Contains the contents of the drop-down list)

PHP file

The server page called above through JavaScript is named "getuser.php " PHP file.

The source code in "getuser.php" will run a query against the MySQL database and return the results in an HTML table:

  Firstname Lastname Age Hometown Job "; while($row = mysqli_fetch_array($result)) { echo ""; echo "" . $row['FirstName'] . ""; echo "" . $row['LastName'] . ""; echo "" . $row['Age'] . ""; echo "" . $row['Hometown'] . ""; echo "" . $row['Job'] . ""; echo ""; } echo ""; mysqli_close($con); ?>

Explanation:When the query starts from When JavaScript is sent to a PHP file, what happens is:

1. PHP opens a connection to the MySQL database

2. Finds the selected user

3. Creates the HTML table, Fill in the data and send back the "txtHint" placeholder