How to Dynamically Redraw a Google Chart Using AJAX and a User-Selected Table?

Redraw Google Chart Based on User Input via AJAX Request

The goal is to seamlessly update a Google chart with data pulled from a selected table in a drop-down menu using AJAX. However, an error arises due to the jQuery $ function being undefined.

Problem Analysis:

The original code used a GET request in the URL to fetch data for the chart. However, when the data needs to be sourced dynamically via AJAX, the required data cannot be accessed without altering the script structure.

Solution Implementation:

1. Web Page Modification:

   • Add a drop-down menu to select the desired table.
   • Attach an event listener to the selection change event to trigger AJAX data retrieval.

2. AJAX Request:

   • Implement an AJAX request to get the desired data from a designated PHP file, getdata.php.
   • Ensure that the response from the PHP file is in a format acceptable by Google charts, such as JSON.

3. PHP File (getdata.php):

   • Retrieve the selected table name from the AJAX request.
   • Retrieve and format the data from the database table into a format that Google charts can interpret (e.g., JSON).
   • Output the formatted data in the JSON format.

4. Chart Redraw Logic:

   • Use the data obtained from the AJAX request to create a new Google Visualization DataTable.
   • Utilize the draw() method of Google Visualization to update the chart with the new data.

Additional Considerations:

• It's recommended to use a modern JavaScript framework for more efficient code organization.
• Consider using a server-side database driver instead of direct MySQL calls for increased security.

Example Code:

HTML/JavaScript:

PHP (getdata.php):

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