[英]Entity Framework Select Collection of Related Entities as Their Own List
這是我針對該問題的數據庫表:
鑒於我已經選擇了一個WorkReleaseHeader,現在我想要獲取與該WorkReleaseHeader相關的WorkOrderDetails的列表。 看起來很容易,但是我無法實現。 我可行的嘗試:
List<WorkReleaseDetail> workReleaseDetails =
((IEnumerable<WorkReleaseDetail>)wrkRlsHdr.WorkReleaseDetails).ToList();
List<WorkOrderDetail> workOrderDtlsForWorkRelease =
workReleaseDetails
.Select(wrkDtls => wrkDtls.WorkOrderHeader.WorkOrderDetails).ToList();
在Select語句行上導致錯誤:
Error 3 Cannot implicitly convert type
'System.Collections.Generic.List<System.Collections.Generic.ICollection<WorkOrderDetail>>'
to 'System.Collections.Generic.List<WorkOrderDetail>'
我認為這應該工作:
List<WorkOrderDetail> workOrderDtlsForWorkRelease =
workReleaseDetails
.SelectMany(wrkDtls => wrkDtls.WorkOrderHeader.WorkOrderDetails).ToList();
LINQ中的SelectMany可以平鋪您的列表,因此在您的示例中,您將沒有列表的集合。
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