Sunday, August 17, 2008

PHP MySQL The Where Clause

The WHERE clause

To select only data that matches a specific criteria, add a WHERE clause to the SELECT statement.

Syntax
SELECT column FROM table
WHERE column operator value


The following operators can be used with the WHERE clause:



Operator


Description



=

Equal



!=

Not equal



>

Greater than



<

Less than



>=

Greater than or equal



<=

Less than or equal



BETWEEN

Between an inclusive range



LIKE

Search for a pattern



Note: SQL statements are not case sensitive. WHERE is the same as where.



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


The following example will select all rows from the "Person" table, where FirstName='Peter':



<?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 person
WHERE FirstName='Peter'");

while($row = mysql_fetch_array($result))
{
echo $row['FirstName'] . " " . $row['LastName'];
echo "<br />";
}

?>


The output of the code above will be:



Peter Griffin

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