如果 POST['submitted_field'] 不是 Null MariaDB、MySQL，则更新行字段

Question

Hi I'm trying to update user information on valid submit in my query it's possible to update multiple columns only if it's relevant $_POST[ ] is not null how i can do that? used tool php, MariaDB or mysql I. I tried something like this but it returns syntax error corresponding to MariaDB

 $query = " UPDATE `users`
            SET name = COALESCE($name, name),
            title = COALESCE($title, title),
            email = COALESCE($email, email),
            gender = COALESCE($gender, gender)
            WHERE `id` = '" . $_SESSION['id'] . "'   LIMIT 1";

Answer 1

You can have a helper for doing that

function getUserUpdateQuery(array $data, $userId)
{
    $condition = 'WHERE id = '.$userId;
    $query = 'UPDATE `users` SET ';
    $updates = [];

    foreach ($data as $columnName => $columnValue) {
        if( !is_null($columnValue) )
        {
            $updates[] = sprintf('`%s` = \'%s\'', $columnName, $columnValue);
        }
    }

    $query .= implode(' AND ', $updates).' ';

    $query .= $condition;

    return $query;
}

$query = getUserUpdateQuery(['title' => $title, 'email' => $email], $_SESSION['id']);

// updating codes here

Note: in production environment it is better practice to bind data. PDO is a good tool for doing that.