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MySQLi – Delete Query

If you want to delete a record from any MySQL table, then you can use the SQL command DELETE FROM. You can use this command at the mysql> prompt as well as in any script like PHP.

Syntax

The following code block has a generic SQL syntax of the DELETE command to delete data from a MySQL table.

DELETE FROM table_name [WHERE Clause]
  • If the WHERE clause is not specified, then all the records will be deleted from the given MySQL table.
  • You can specify any condition using the WHERE clause.
  • You can delete records in a single table at a time.

The WHERE clause is very useful when you want to delete selected rows in a table.

Deleting Data from the Command Prompt

This will use the SQL DELETE command with the WHERE clause to delete selected data into the MySQL table – Adglob_tbl.

Example

The following example will delete a record from the Adglob_tbl whose Adglob_id is 3.

root@host# mysql -u root -p password;
Enter password:*******

mysql> use ADGLOB;
Database changed

mysql> DELETE FROM Adglob_tbl WHERE Adglob_id=3;
Query OK, 1 row affected (0.23 sec)

mysql>

Deleting Data Using a PHP Script

PHP uses mysqli query() or mysql_query() function to delete records in a MySQL table. This function takes two parameters and returns TRUE on success or FALSE on failure.

Syntax

$mysqli→query($sql,$resultmode)
Sr.No.Parameter & Description
1$sqlRequired – SQL query to delete records in a MySQL table.
2$resultmodeOptional – Either the constant MYSQLI_USE_RESULT or MYSQLI_STORE_RESULT depending on the desired behavior. By default, MYSQLI_STORE_RESULT is used.

Example

Try the following example to delete a record in a table −

Copy and paste the following example as mysql_example.php −

<html>
   <head>
      <title>Deleting MySQL Table record</title>
   </head>
   <body>
      <?php
         $dbhost = 'localhost';
         $dbuser = 'root';
         $dbpass = 'root@123';
         $dbname = 'ADGLOB';
         $mysqli = new mysqli($dbhost, $dbuser, $dbpass, $dbname);
         
         if($mysqli→connect_errno ) {
            printf("Connect failed: %s<br />", $mysqli→connect_error);
            exit();
         }
         printf('Connected successfully.<br />');
		 
         if ($mysqli→query('DELETE FROM Adglob_tbl where Adglob_id = 4')) {
            printf("Table Adglob_tbl record deleted successfully.<br />");
         }
         if ($mysqli→errno) {
            printf("Could not delete record from table: %s<br />", $mysqli→error);
         }
   
         $sql = "SELECT Adglob_id, Adglob_title, Adglob_author, submission_date FROM Adglob_tbl";
		 
         $result = $mysqli→query($sql);
           
         if ($result→num_rows > 0) {
            while($row = $result→fetch_assoc()) {
               printf("Id: %s, Title: %s, Author: %s, Date: %d <br />", 
                  $row["Adglob_id"], 
                  $row["Adglob_title"], 
                  $row["Adglob_author"],
                  $row["submission_date"]);               
            }
         } else {
            printf('No record found.<br />');
         }
         mysqli_free_result($result);
         $mysqli→close();
      ?>
   </body>
</html>

Output

Access the mysql_example.php deployed on apache web server and verify the output. Here we’ve entered multiple records in the table before running the select script.

Connected successfully.
Table Adglob_tbl record deleted successfully.
Id: 1, Title: MySQL Adglob, Author: Jay, Date: 2021
Id: 2, Title: HTML Adglob, Author: Jay, Date: 2021
Id: 3, Title: PHP Adglob, Author: Jay, Date: 2021
Id: 5, Title: Apache Adglob, Author: Subu, Date: 2021

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