PHP MySQL :: Delete Data In a Database

The DELETE statement is used to delete records in a table.

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Delete Data In a Database

The DELETE FROM statement is used to delete records from a database table.

Syntax

DELETE FROM table_name WHERE some_column = some_value

Note: Notice the WHERE clause in the DELETE syntax. The WHERE clause specifies which record or records that should be deleted. If you omit the WHERE clause, all records will be deleted!

To get PHP to execute the statement above we must use the mysql_query() function. This function is used to send a query or command to a MySQL connection.

Example

Look at the following "Persons" table:

FirstName	LastName	Age
Peter	Griffin	35
Glenn	Quagmire	33

The following example deletes all the records in the "Persons" table where LastName='Griffin':

<?php $con = mysql_connect("localhost","peter","abc123"); if (!$con)   {   die('Could not connect: ' . mysql_error());   } mysql_select_db("my_db", $con); mysql_query("DELETE FROM Persons WHERE LastName='Griffin'"); mysql_close($con); ?>

After the deletion, the table will look like this:

FirstName	LastName	Age
Glenn	Quagmire	33

PHP MySQL :: ORDER BY Keyword

The ORDER BY keyword is used to sort the data in a recordset.

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The ORDER BY Keyword

The ORDER BY keyword is used to sort the data in a recordset.

The ORDER BY keyword sort the records in ascending order by default.

If you want to sort the records in a descending order, you can use the DESC keyword.

Syntax

SELECT column_name(s) FROM table_name ORDER BY column_name(s) ASC|DESC

To learn more about SQL, please visit our SQL tutorial.

Example

The following example selects all the data stored in the "Persons" table, and sorts the result by the "Age" column:

<?php $con = mysql_connect("localhost","peter","abc123"); if (!$con)   {   die('Could not connect: ' . mysql_error());   } mysql_select_db("my_db", $con); $result = mysql_query("SELECT * FROM Persons ORDER BY age"); while($row = mysql_fetch_array($result))   {   echo $row['FirstName'];   echo " " . $row['LastName'];   echo " " . $row['Age'];   echo "<br />";   } mysql_close($con); ?>

The output of the code above will be:

Glenn Quagmire 33 Peter Griffin 35

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Order by Two Columns

It is also possible to order by more than one column. When ordering by more than one column, the second column is only used if the values in the first column are equal:

SELECT column_name(s) FROM table_name ORDER BY column1, column2