In our previous set of articles, we’ve created a simple 2 page website that allows users to submit comments about the page they were looking at. In this article, we’re going to show you how to use PHP to Connect to and Retrieve Data from MySQL. In order to display comments on a page, we first need to know what comments to show. When we setup our site we created two pages, and each page was assigned a unique id number. This ID number will be used to gather comments for that specific page. For example, when the user is on page 1, we’ll select all of the comments in the database assigned to page “1”. If you’re not familiar with SQL, you can use phpMyAdmin to help write your SQL
command. To do this:
Step 2. Setting up our PHP code to SELECT our commentsNote that mysqli_fetch_array was deprecated in PHP versions below 7.0. As of 7.0, the code has been removed and replaced with mysqli_fetch-array. Now that we have our sample SQL query, we can use it to create the php code that will print all comments on a page. Below is the example code that we created. If you’re not familiar with php, any line that begins with a // is a comment, and comments are used by developers to document their code. In our example, we have quite a few comments to help explain what the code is doing, but keep in mind that most scripts do not have as many comments.
As stated earlier, we purposely include many comments to help explain what the code was doing. While the example code above looks like a lot of work, if we strip out all of the comments, the code looks more like:
Step 3. Placing our php code into our pagesWe now have our php code that will display comments to the screen. In a previous article, we explained how to use php’s include function to reuse code, and we will continue to use this method to use our php code. To incorporate our php code:
After performing the steps above, our page1.php file now looks like this:
After testing our two pages, you can see that each page shows only the comments that were added to that particular page:
How can I fetch all data from a table in PHP?The fetch_all() / mysqli_fetch_all() function fetches all result rows and returns the result-set as an associative array, a numeric array, or both.
How do you retrieve data from database in PHP using MySQLi?Fetching Data Using a PHP Script
PHP uses mysqli query() or mysql_query() function to select records from a MySQL table. This function takes two parameters and returns TRUE on success or FALSE on failure.
How do you retrieve data from a database?Fetch data from a database. Start by creating a new app.. Add a Screen to your app. ... . Add data sources to your app by referencing some Entities in the Manage Dependencies window (Ctrl+Q). ... . Publish the app by clicking the 1-Click Publish button. ... . It's time to load some data to the Screen.. |