The DELETE command deletes table rows from the specified table, and returns the quantity deleted. Access the quantity deleted with the ROW_COUNT() function. A WHERE clause specifies rows and in its absence, all rows are deleted. A LIMIT clause controls the number of rows deleted.
In a DELETE statement for multiple rows, it deletes only those rows satisfying a condition; and LIMIT and WHERE clauses are not permitted. DELETE statements allow deleting rows from tables in different databases, but do not allow deleting from a table and then selecting from the same table within a subquery.
Review the following DELETE syntax −
DELETE FROM table_name [WHERE …]
Execute a DELETE command from either the command prompt or using a PHP script.
The Command Prompt
At the command prompt, simply use a standard command −
root@host# mysql –u root –p password; Enter password:******* mysql> use PRODUCTS; Database changed mysql> DELETE FROM products_tbl WHERE product_id=133; mysql> SELECT * from products_tbl WHERE ID_number='133'; ERROR 1032 (HY000): Can't find record in 'products_tbl'
PHP Delete Query Script
Use the mysql_query() function in DELETE command statements −
<?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 products_tbl WHERE product_id = 261'; mysql_select_db('PRODUCTS'); $retval = mysql_query( $sql, $conn ); if(! $retval ) { die('Could not delete data: ' . mysql_error()); } echo "Deleted data successfully\n"; mysql_close($conn); ?>
On successful data deletion, you will see the following output −
mysql> Deleted data successfully mysql> SELECT * from products_tbl WHERE ID_number='261'; ERROR 1032 (HY000): Can't find record in 'products_tbl'
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