PHP检查MySQL选择是否存在或为空

Question

i'm trying to make a check to show content or not:

$stmt = $mysqli->prepare("SELECT *
        FROM friends
        WHERE friendID = ?
        AND userID = ?");

$stmt->bind_param('ii', $id, $connectedUserID);
$stmt->execute();

if (login_check($mysqli) == true && $stmt->num_rows > 0) {
    //do something
} else echo 'you are not allowed to be here';

I want to check if there's any row with those two ids.

But it's not working, i tried many different ways like using === or !== false.

Any help?

Ty!

Answer 1

Try using a simple '=' or declare a boolean variable and set it 'true' and then compare

Also read:

• PHP: Comparison Operators
• PHP: Logical Operatos

Answer 2

Most likely login check does not return true, the following should be enough

if(isset($id, $connectedUserID)){
    $stmt = $mysqli->prepare("SELECT *
            FROM friends
            WHERE friendID = ?
            AND userID = ?");

    $stmt->bind_param('ii', $id, $connectedUserID);
    $stmt->execute();

    $stmt->execute();
    if ($stmt->num_rows > 0) {
        //do something
    } else{
        echo 'you are not allowed to be here';
    }
}else{
    //redirect to login
}

If the user need to be logged in then this is not the place to check for that, it should be prior to this query.