c# - 微软动态 CRM 2016

Question

我正在尝试编写一个 fetch xml 以从 Facility/Equipment Entity 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空引用异常/System.NullReferenceException（粗体行）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"];
}

有人可以建议我吗？提前致谢！

Answer 1

您businessunitid还需要在属性中添加，而不仅仅是在条件中：

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>";