I use the following code to access the id for the last inserted item but can only get 0 for relatedAccountID. May I ask if anyone can point out the issue? Many Thanks.

It continues showing 0 with executing the code

Thanks for the support from the post:

CodePudding user response：

if ($conn) {
    return $conn;
}

should be

if (self::$conn) {
    return self::$conn;
}