小编Kar*_*arl的帖子

我想离开连接两个表并总结一个字段,所以我做了这个查询:

IQueryable<Reference.Inventory.SearchDetailRequester> _qRequester =
    from a in dbErp.EPROC_TR_ER_DETAIL
    join b in dbErp.EPROC_TR_INVENTORY on
    new Reference.Inventory.SearchDetailRequester { ID_REQUEST = a.ID_REQUEST , ID_KATALOG = a.ID_KATALOG}
    equals
    new Reference.Inventory.SearchDetailRequester { ID_REQUEST = b.ID_REQUEST, ID_KATALOG = b.ID_KATALOG }
    into inv_join 
    from c in inv_join.DefaultIfEmpty()
    where a.ID_REQUEST == ID_REQUEST && a.APROVE_BY_DS == 1 && a.APROVE_BY_GS == 1

    select new Reference.Inventory.SearchDetailRequester
    {
        ID_KATALOG = a.ID_KATALOG,
        TYPE_OF_GGS = a.TYPE_OF_GGS,
        TRANSACTION_TYPE = "OUT",
        DATE = c.DATE ?? "",
        QTY = -1 * c.QTY ?? a.QTY,
        ID_INVENTORY = c.ID_INVENTORY, …