PHP mysqli code to delete data from the database

This article is created to describe the way to delete or remove the data from a MySQL database using PHP mysqli object-oriented and procedural script.

Either we approach object-oriented or procedural, the steps to delete data from a database are the same, namely:

• Open a connection to the database.
• Write an SQL statement regarding the data deletion.
• Initialize it as a variable.
• Use this variable to perform the data deletion query against the MySQL database.
• Close the connection to the database.

Note: Be careful when deleting the data from the database. Always use the WHERE clause to delete a specific record (row). Otherwise, the whole record will be deleted.

Before writing and executing the PHP mysqli script to delete data from the database, let me show you the table I am going to work with in this article:

PHP mysqli object-oriented script to delete data from the database

<?php
   $server = "localhost";
   $user = "root";
   $pass = "";
   $db = "codescracker";
   
   $conn = new mysqli($server, $user, $pass, $db);
   
   if($conn->connect_errno)
   {
      echo "Database connection failed!<BR>";
      echo "Reason: ", $conn->connect_error;
      exit();
   }
   
   $sql = "DELETE FROM `customer` WHERE id='3'";
   
   $qry = $conn->query($sql);
   if($qry)
   {
      echo "Data deleted successfully.";
      
      // block of code to process further
   }
   else
   {
      echo "Something went wrong!<BR>";
      echo "Error Description: ", $conn->error;
   }
   $conn->close();
?>

The output produced by the above PHP example of deleting data from a database is shown in the snapshot given below:

And after executing the above script, here is the new snapshot of the table named "customer":

Note: The mysqli() function is used to open a connection to the MySQL database server in object-oriented style.

Note: The new keyword is used to create a new object.

Note: The connect_errno is used to get or return the error code (if any) from the last connect call in object-oriented style.

Note: The connect_error is used to get the error description (if any) from the last connection in object-oriented style.

Note: The exit() function is used to terminate the execution of the current PHP script.

Note: The query() function is used to perform queries on the MySQL database in object-oriented style.

Note: The error is used to return the description of the error (if any) from the most recent function call in object-oriented style.

Note: The close() function is used to close an opened connection in object-oriented style.

The above example can also be written in this way:

<?php
   $conn = new mysqli("localhost", "root", "", "codescracker");
   
   if(!$conn->connect_errno)
      $qry = $conn->query("DELETE FROM `customer` WHERE id='5'");
   
   $conn->close();
?>

PHP mysqli procedural script to delete data from the database

<?php
   $conn = mysqli_connect("localhost", "root", "", "codescracker");
   
   if(!mysqli_connect_errno())
   {
      $sql = "DELETE FROM `customer` WHERE id='3'";
      
      if(mysqli_query($conn, $sql))
      {
         echo "Data removed successfully.";
         // block of code to process further
      }
   }
   mysqli_close($conn);
?>

Note: The mysqli_connect() function is used to open a connection to the MySQL database server in procedural style.

Note: The mysqli_connect_errno() function is used to get or return the error code (if any) from the last connect call in procedural style.

Note: The mysqli_query() function is used to perform queries on the MySQL database in procedural style.

Note: The mysqli_close() function is used to close an opened connection to the MySQL database in procedural style.

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