无法从PHP将Null插入数据库

Question

I'm trying to insert NUll into database everything is working fine but null is not inserted.

below query for the same.

#update permissions for deleted user and make it to NULL
$edit_user_permission = $conn->prepare('update create_user set permission = ? where role_id = ?');
$edit_user_permission->bind_param("ss",$permission,$role_id);
$permission = NULL;
$role_id = $_SESSION['role_code'];
$edit_user_permission->execute();

below structure of Permission column in the database

Answer 1

I thing the issue is in parameter binding.So just change the parameter binding format.Do something like this

$edit_user_permission = $conn->prepare('update create_user set permission = ? where role_id = ?');
$edit_user_permission->bindParam(1, $permission);
$edit_user_permission->bindParam(2, $role_id);
$permission = NULL;
$role_id = $_SESSION['role_code'];
$edit_user_permission->execute();

It will help you. You can refer prepared-statements.php

Modified

$edit_user_permission->bind_param(1, $permission);
$edit_user_permission->bind_param(2, $role_id);

Try this one.