Microsoft Dynamics CRM 2016

Question

我正在尝试编写一个fetch xml来从Facility / Equipment Entity中检索BusinessUnitID和Equipment ID，我已经在c＃代码中编写了这个fetch xml，但它在行中抛出了一个null引用异常/ System.NullReferenceException（BOLD' ed line） 我在设施/设备实体中没有任何空值。 这是我的代码：

  private static OrganizationService _orgService;
  string fetchBU = @"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>
    <entity name='equipment'>
        <attribute name='name' />
        <attribute name='equipmentid' />
        <order attribute='name' descending='false' />
      <filter type='and'>
         <condition attribute='businessunitid' operator='eq-businessid' />
      </filter>
    </entity>
   </fetch>";

EntityCollection ec = _orgService.RetrieveMultiple(new FetchExpression(fetchBU));
if (ec.Entities.Count > 0)
{
   Guid BusinessUnitId = (Guid)ec[0].Attributes["businessunitid"];
}

有人可以就此建议我吗？ 提前谢谢！

Answer 1

您还需要在属性中添加businessunitid，而不仅仅是条件：

string fetchBU = @"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='false'>
    <entity name='equipment'>
        <attribute name='name' />
        <attribute name='equipmentid' />
        <attribute name='businessunitid' />
        <order attribute='name' descending='false' />
      <filter type='and'>
         <condition attribute='businessunitid' operator='eq-businessid' />
      </filter>
    </entity>
   </fetch>";