The WHERE clause

The WHERE clause

The WHERE clause is used to extract only those records that fulfill a specified criterion.

Syntax

SELECT column_name(s)

FROM table_name

WHERE column_name operator value

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

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 selects all rows from the "Persons" table where "FirstName='Peter':

$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

WHERE FirstName='Peter'");

while($row = mysql_fetch_array($result))

  {

  echo $row['FirstName'] . " " . $row['LastName'];

  echo "
";

  }

?>

The output of the code above will be:

Peter Griffin