The function prepare() prepares an SQL statement. If the statement is valid the function return a resource otherwise it returns false.

/*
 * Connection to Oracle database
*/
 
$handle = $db->prepare('SELECT * FROM customers WHERE customer_no=?');
 
$params = array(0=>100);
 
/*
* Send an array to execute
*/
$result = $db->execute(array($handle,$params));

For compatibility purposes, if the database does not support prepared statements, the SQL statement is returned into the $handle variable. When sent to the execute() function, The statement will be parsed to include the variables, and the statement will execute the same as if passed without parameters, and as if the DBMS supported prepared statements.