A表
ItemID ID1, ID2, ID3, ID4, F1,F2,F3
A001 kg kg m kgB表
ItemID From To Factor
A001 kg kg 1
A001 m kg 2现在想求得是,a表的ID1->ID4, ID2->ID4, ID3->ID4 之间的转换结果就是
ItemID ID1, ID2, ID3, ID4, F1,F2,F3
A001 kg kg m kg 1 1 2
ItemID ID1, ID2, ID3, ID4, F1,F2,F3
A001 kg kg m kgB表
ItemID From To Factor
A001 kg kg 1
A001 m kg 2现在想求得是,a表的ID1->ID4, ID2->ID4, ID3->ID4 之间的转换结果就是
ItemID ID1, ID2, ID3, ID4, F1,F2,F3
A001 kg kg m kg 1 1 2
ItemID NVarchar(100),
ID1 Nvarchar(5),
ID2 Nvarchar(5),
ID3 Nvarchar(5),
ID4 Nvarchar(5))Insert Into @TmpDataA
Select 'A001','kg','kg','m','kg'Declare @TmpDataB Table(
ItemID NVarchar(100),
FromS Nvarchar(5),
ToS NVarchar(5),
Factor Int)
Insert Into @TmpDataB
Select 'A001','kg','kg',1
Union
Select 'A001','m','kg',2Select A.ItemID,A.ID1,A.ID2,A.ID3,A.ID4,Sum(F1) As F1,Sum(F2) As F2,Sum(F3) AsF3 From (
Select A.*,B.Factor As F1,0 As F2,0 As F3
From @TmpDataA A
Inner Join @TmpDataB B On B.ItemID = A.ItemID And B.FromS = A.ID1 And B.ToS = A.ID4
Union All
Select A.*,0 As F1,B.Factor As F2,0 As F3
From @TmpDataA A
Inner Join @TmpDataB B On B.ItemID = A.ItemID And B.FromS = A.ID2 And B.ToS = A.ID4
Union All
Select A.*,0 As F1,0 As F2,B.Factor As F3
From @TmpDataA A
Inner Join @TmpDataB B On B.ItemID = A.ItemID And B.FromS = A.ID3 And B.ToS = A.ID4) A
Group By A.ItemID,A.ID1,A.ID2,A.ID3,A.ID4
SELECT A.ItemID,A.ID1,A.ID2,A.ID3,A.ID4
,T1.Factor F1,T2.Factor F2,T3.Factor F3
FROM A
LEFT JOIN B T1 ON A.ItemID=T1.ItemID AND A.ID1=T1.[From] AND A.ID4=T1.[To]
LEFT JOIN B T2 ON A.ItemID=T2.ItemID AND A.ID2=T2.[From] AND A.ID4=T2.[To]
LEFT JOIN B T3 ON A.ItemID=T3.ItemID AND A.ID3=T3.[From] AND A.ID4=T3.[To]--更新方式
UPDATE A
SET F1=T1.Factor,F2=T2.Factor,F3=T3.Factor
FROM A
LEFT JOIN B T1 ON A.ItemID=T1.ItemID AND A.ID1=T1.[From] AND A.ID4=T1.[To]
LEFT JOIN B T2 ON A.ItemID=T2.ItemID AND A.ID2=T2.[From] AND A.ID4=T2.[To]
LEFT JOIN B T3 ON A.ItemID=T3.ItemID AND A.ID3=T3.[From] AND A.ID4=T3.[To]
SELECT A.ItemID,A.ID1,A.ID2,A.ID3,A.ID4
,T1.Factor F1,T2.Factor F2,T3.Factor F3
FROM A
LEFT JOIN B T1 ON A.ItemID=T1.ItemID AND A.ID1=T1.[From] AND A.ID4=T1.[To]
LEFT JOIN B T2 ON A.ItemID=T2.ItemID AND A.ID2=T2.[From] AND A.ID4=T2.[To]
LEFT JOIN B T3 ON A.ItemID=T3.ItemID AND A.ID3=T3.[From] AND A.ID4=T3.[To]
这种方式的话,对B表是检索一次还是多次呢, 如果B表数据量很大,就会很慢吧