PDO mysql选择查询未执行

Question

Why is this PDO not executing?

$statement = $db->prepare("select * from quest where id = :'"+$testno+"'");
$statement->execute();
$row = $statement->fetch(PDO::FETCH_ASSOC); 

echo "Q:".$row["questions"];

The "Q" is not echoed.

Answer 1

You should put named placeholder in prepared sql and bind it to desired value later:

$statement = $db->prepare("select * from quest where id = :id");
$statement->bindParam(':id', $testno, \PDO::PARAM_INT);
$statement->execute();
$row = $statement->fetch(PDO::FETCH_ASSOC); 

echo "Q:".$row["questions"];

Assuming id is integer, if not - replace \\PDO::PARAM_INT with \\PDO::PARAM_STR .

Answer 2

$statement = $db->prepare("select * from quest where id = :testno");
$statement->execute(array(':testno'=>$testno));
$row = $statement->fetch(PDO::FETCH_ASSOC); 

echo "Q:".$row["questions"];

Answer 3

@X10nD, Simply use like below code... :)

$query = "SELECT * FROM quest WHERE id = ?";
$statement = $db->prepare($query);
$statement->bindParam(1,$testno);
$statement->execute();
$row = $statement->fetch(PDO::FETCH_ASSOC); 

echo "Q:".$row['questions'];