Question

I am trying out PDO in PHP for the first time. I thought that PDOStatement->bindParam() would be a cool way to set the datatypes of the values that i pass in to the sql query. But somehow it doesnt work for me. For example I set the type of a variable to INT in bindParam call. But it still doesnt throw error even when I pass pure string values to it. Maybe I am doing something wrong. Here is the snippet of the code..

$query = "select * from PDO_TABLE where A_COLUMN = :test1 or B_COLUMN = :test2";

$test1 = '0';
$test2 = 'a';
$preparedStatement = $conn->prepare($query);

echo $preparedStatement->bindParam(':test1', $test1, PDO::PARAM_INT);
echo $preparedStatement->bindParam(':test2', $test2, PDO::PARAM_INT);

$preparedStatement->execute();

Am I doing everything properly? Isnt this supposed to throw error for the parameter test2?

Answer 1

PDO won’t throw an exception or raise an error but at best convert the parameter to an integer/long.
E.g. in pdo_stmt.c:

if (PDO_PARAM_TYPE(param->param_type) == PDO_PARAM_INT && Z_TYPE_P(param->parameter) == IS_BOOL) {
  convert_to_long(param->parameter);
}

i.e. if you have registered a parameter as PDO_INT but the variable holds a boolean PDO converts the bool to an int/long.