我使用GroupBy对像这样的对象进行分组:
SELECT TOP 1
t.Id ,
t.OId ,
t.Amount ,
t.DUserId,
t.StartDate ,
t.ExtDesc,
t.StatusId
FROM dbo.[Transaction] t
JOIN dbo.Wallet cw ON t.CId = cw.Id
JOIN dbo.Wallet dw ON t.DId = dw.Id
WHERE ExtKey = @ExtKey
AND ( cw.vId = @vId
OR dw.VId = @vId
)
--Second Selct which executes twice with differenc params
SELECT u.Id ,
UserName ,
PinCode ,
CurrencyId ,
StatusId ,
PersonalNumber ,
gu.DefaultVendorServiceId ,
CountryId,
u.FirstName,
u.LastName
FROM dbo.[User] u
LEFT JOIN dbo.GamblerUser gu ON gu.UserId = u.Id
WHERE u.Id = @UserId
--Last select with (updlock)
SELECT w.Id, AccountNo, FundTypeId, VendorServiceId, Balance, UserId, vs.IsLocalAccount
FROM Wallet w (UPDLOCK)
JOIN VendorService vs on w.VId = vs.Id
WHERE
w.UserId = @UserId
AND w.FundTypeId = @FundTypeId
AND w.VendorServiceId = @VendorServiceId
-- Insert
INSERT INTO [dbo].[Transaction]
( StartDate ,
OTypeId ,
StatusId ,
Amount ,
ExtDesc,
DUserId
)
VALUES ( @StartDate ,
@OTypeId ,
@StatusId ,
@Amount ,
@ExtDesc,
@DUserId
)
SET @Id = ( SELECT @@IDENTITY
)
-- Update on updlocked table
UPDATE dbo.Wallet SET
Balance = ISNULL(@Balance, Balance)
WHERE Id = @Id
一切正常。
但现在我想将Specialized为ICollection<>。的对象分组
例如:
var categories=
tovRDb.MyObjects.AsEnumerable().Where(t => myHashSet.Contains(t.Id))
.GroupBy(t => t.Specialization, t => t,
(key, g) => new {Name = key.Name, CategoryItems = g.ToList()})
.OrderBy(t => string.IsNullOrEmpty(t.Name))
.ThenBy(t => t.Name)
.ToList();
分组后:
MyObject1: "Berlay's Meat"
Specializations{Chicken, Pork, Beef}
MyObject2: "Wonday's Chickery"
Specializations{Chicken}
MyObject3: "Rooki's Meat"
Specializations{Chicken, Pork}
有任何建议吗?
答案 0 :(得分:2)
categories
为:
var categories = tovRDb.MyObjects.AsEnumerable().Where(t => myHashSet.Contains(t.Id));
var catsGrouped = categories.SelectMany(
x => x.Specializations, // Specializations is an IEnumerable<Specialization>
(x, y) => new
{
Category = x,
Specialization = y,
}).GroupBy(x => x.Specialization, x => x.Category)
.ToArray();
我使用SelectMany
来&#34;乘以&#34;每个类别的专业化......然后我按Specialization
重新分组结果。结果是IGrouping<Specialization, MyObject>[]