我在我的舊專案中將我的專案轉換為 EF Core，我正在運行一個查詢。
IDictionary<int, IGrouping<int, UserPurchaseItemAddonWithAmount>> addons =
context.Fetch<UserPurchaseItemAddonWithAmount>($"Select UPIA.*, EA.Amount From UserPurchaseItemAddons UPIA Inner Join ExtraAddons EA on UPIA.AddonID = EA.AddonID Where UPIA.UserPurchaseItemID in ({string.Join(',', userPurchaseItems.Select(S => S.UserPurchaseItemID))})")
.GroupBy(G => G.UserPurchaseItemID).ToDictionary(D => D.Key);
我需要將此查詢轉換為 Linq 查詢我在做什么如下
IDictionary<int, IGrouping<int, UserPurchaseItemAddonWithAmount>> addons =
(from f in context.UserPurchaseItemAddons
join s in context.ExtraAddons
on f.AddonId equals s.AddonId
select new
{
Amount = s.Amount,
UserPurchaseItemAddonID = f.UserPurchaseItemAddonId,
UserPurchaseItemID = f.UserPurchaseItemId,
BranchItemVariantID = f.BranchItemVariantId,
AddonID = f.AddonId,
UserID = f.UserId,
IsDeleted = f.IsDeleted,
ModifiedOn = f.ModifiedOn,
ModifiedBy = f.ModifiedBy,
Reason = f.Reason,
}).GroupBy(G => G.UserPurchaseItemID).ToDictionary(D => D.Key);
此查詢導致與轉換為IGrouping<int, UserPurchaseItemAddonWithAmount>匿名型別相關的編譯器錯誤。另一件事是我如何在上述查詢中的 where 條件中應用 in 子句，就像第一個查詢一樣。
班級
public class UserPurchaseItemAddonWithAmount
{
public decimal Amount { get; set; }
public int UserPurchaseItemAddonID { get; set; }
public int UserPurchaseItemID { get; set; }
public int BranchItemVariantID { get; set; }
public int AddonID { get; set; }
public int UserID { get; set; }
public bool IsDeleted { get; set; }
public DateTime? ModifiedOn { get; set; }
public int? ModifiedBy { get; set; }
public string? Reason { get; set; }
}
uj5u.com熱心網友回復：
嘗試以下查詢。您回傳匿名類的主要錯誤。
var purchaseItemIds = userPurchaseItems.Select(S => S.UserPurchaseItemID);
IDictionary<int, IGrouping<int, UserPurchaseItemAddonWithAmount>> addons =
(from f in context.UserPurchaseItemAddons
join s in context.ExtraAddons on f.AddonId equals s.AddonId
where purchaseItemIds.Contains(f.UserPurchaseItemID)
select new UserPurchaseItemAddonWithAmount
{
Amount = s.Amount,
UserPurchaseItemAddonID = f.UserPurchaseItemAddonId,
UserPurchaseItemID = f.UserPurchaseItemId,
BranchItemVariantID = f.BranchItemVariantId,
AddonID = f.AddonId,
UserID = f.UserId,
IsDeleted = f.IsDeleted,
ModifiedOn = f.ModifiedOn,
ModifiedBy = f.ModifiedBy,
Reason = f.Reason,
})
.AsEnumerable()
.GroupBy(G => G.UserPurchaseItemID)
.ToDictionary(D => D.Key);
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