PHP Beginner's Introduction to AJAX and MYSQL

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

First we need to create a table in the database

As shown in the figure below:

Then we write an html page, the code is as follows:

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

This code must be handed over to demo.php for processing

Note: showUser() The function will perform the following steps:

Check whether a user has been selected

Create an XMLHttpRequest object

Create a function that is executed when the server response is ready

Report to the server Send a request to the file on

Please pay attention to the parameter (q) added to the end of the URL (containing the contents of the drop-down list)

Below we write a deno.php file, the code is as follows:

  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 a query is sent from JavaScript to a PHP file, what happens is:

1. PHP opens a connection to the MySQL database

2. Find the selected user

3. Create an HTML table, fill in the data, and send back the "txtHint" placeholder

Note: You need to copy this code to your own server and then run it See what kind of effect

# Database must be established

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