绑定准备语句的多个参数

Question

My PHP looks like this:

$sql1="SELECT @rownum := @rownum + 1 Rank, q.* FROM (SELECT @rownum:=0) r,(SELECT  * ,sum(`number of cases`) as tot, sum(`number of cases`) * 100 / t.s AS `% of total` FROM `myTable` CROSS JOIN (SELECT SUM(`number of cases`) AS s FROM `myTable` where `type`=:criteria and `condition`=:diagnosis) t where `type`=:criteria and `condition`=:diagnosis group by `name` order by `% of total` desc) q"";
$stmt = $dbh->prepare($sql1);
$stmt->bindParam(':criteria', $search_crit, PDO::PARAM_STR);
$stmt->bindParam(':diagnosis', $diagnosis, PDO::PARAM_STR);
$stmt->execute();
$result1 = $stmt->fetchAll(PDO::FETCH_ASSOC);
header('Content-type: application/json');
echo json_encode($result1);

I'm getting an error on this line: $stmt->execute();

The error says:

PHP Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY093]: Invalid parameter number' in php/rankings.php:39

Stack trace:

"#"0 php/rankings.php(39): PDOStatement->execute()

"#"1 {main} thrown in php/rankings.php on line 39

How can I do fix this? I know I can pass multiple variables with a prepared statement, but I'm not quite sure how to do it.

Answer 1

You can use parameters only once in a query

$sql1="SELECT @rownum := @rownum + 1 Rank, q.* FROM (SELECT @rownum:=0) r,(SELECT  * ,sum(`number of cases`) as tot, sum(`number of cases`) * 100 / t.s AS `% of total` FROM `myTable` CROSS JOIN (SELECT SUM(`number of cases`) AS s FROM `myTable` where `type`=:criteria and `condition`=:diagnosis) t where `type`=:criteria2 and `condition`=:diagnosis2 group by `name` order by `% of total` desc) q";
$stmt = $dbh->prepare($sql1);       
$stmt->execute(array(':criteria' => $search_crit, ':diagnosis' => $diagnosis, ':criteria2' => $search_crit, ':diagnosis2' => $diagnosis));