<?php

class TestCase227677 extends DrupalTestCase {
  function get_info() {
    return array(
      'name' => t('[200824] drupal_write_record can\'t update a column to NULL'),
      'desc' => t('In update mode, drupal_write_record skips entries set to NULL, and thus leaves the previous value in place. There\'s no way to set a column back to NULL.'),
      'group' => t('Drupal 7 Tests'),
    );
  }
  
  function testIssue() {

    // test on scheme 'users'
    $user = $this->drupalCreateUserRolePerm();
    $data = array($this->randomName() => $this->randomName());
    
    $user->data = $data; // 'data' field can be NULL

    drupal_write_record('users', $user, 'uid');
    $result = db_result(db_query("SELECT data FROM {users} WHERE uid = %d", $user->uid));
    $this->assertTrue(!empty($result), 'Check not empty field');

    $user->data = null;

    drupal_write_record('users', $user, 'uid');
    $foo = db_result(db_query("SELECT data FROM {users} WHERE uid = %d", $user->uid));
    $this->assertTrue(empty($result), 'Check empty field');

  }

}