MySQL DELETE Query

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

Syntax:

Here is generic SQL syntax of DELETE command to delete data from a MySQL table:

DELETE FROM table_name [WHERE Clause]
  • If WHERE clause is not specified, then all the records will be deleted from the given MySQL table.

  • You can specify any condition using 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 Command Prompt:

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

Example:

Following example will delete a record into tutorial_tbl whose tutorial_id is 3.

root@host# mysql -u root -p password;
Enter password:*******
mysql> use TUTORIALS;
Database changed
mysql> DELETE FROM tutorials_tbl WHERE tutorial_id=3;
Query OK, 1 row affected (0.23 sec)

mysql>

Deleting Data Using PHP Script:

You can use SQL DELETE command with or without WHERE CLAUSE into PHP function mysql_query(). This function will execute SQL command in similar way it is executed at mysql> prompt.

Example:

Try out the following example to delete a record from tutorial_tbl whose tutorial_id is 3.

<?php
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn )
{
  die('Could not connect: ' . mysql_error());
}
$sql = 'DELETE FROM tutorials_tbl
        WHERE tutorial_id=3';

mysql_select_db('TUTORIALS');
$retval = mysql_query( $sql, $conn );
if(! $retval )
{
  die('Could not delete data: ' . mysql_error());
}
echo "Deleted data successfully\n";
mysql_close($conn);
?>


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