问题
I have a problem in query data from database to make report in VB.NET. I use the Business Object to do the report. And here is my example data:
___________________________________________________________________________
| | | | | | |
| Id | Item | Unit | Unit Price | Quantity | Amount |
|____|_______________|__________|_____________|___________|_______________|
| 1 | Gasoline | L | $ 2.00 | 10 | $ 20.00 |
| 1 | Gasoline | L | $ 2.50 | 20 | $ 50.00 |
| 2 | Water | Bottle | $ 5.00 | 10 | $ 50.00 |
| 3 | Meat | Kg | $ 14.90 | 15 | $ 223.50 |
| 1 | Gasoline | L | $ 8.00 | 50 | $ 400.00 |
| 4 | Milk | Can | $ 7.45 | 30 | $ 223.50 |
| 1 | Gasoline | L | $ 6.99 | 10 | $ 69.90 |
|____|_______________|__________|_____________|___________|_______________|
In report, I want to see the "Id" , "Item" , "Unit" , "Unit Price" (And yes, this one I will show "Undefined" instead if they have the different value), "Quantity" (Sum of the same item) and "Amount" (Sum of the same item). But I have tried a few times, the result is wrong. How to calculate the "Amount" all the same item, if their "Unit Price" are not the same price at all. Here is my expected result:
___________________________________________________________________________
| | | | | | |
| Id | Item | Unit | Unit Price | Quantity | Amount |
|____|_______________|__________|_____________|___________|_______________|
| 1 | Gasoline | L | Undefined | 90 | $ 539.90 |
| 2 | Water | Bottle | $ 5.00 | 10 | $ 50.00 |
| 3 | Meat | Kg | $ 14.90 | 15 | $ 223.50 |
| 4 | Milk | Can | $ 7.45 | 30 | $ 223.50 |
|____|_______________|__________|_____________|___________|_______________|
Please help me....
回答1:
If I understood you correctly, this should do what you want:
SELECT A.Id,
A.Item,
A.Unit,
CASE WHEN B.Id IS NOT NULL THEN 'Undefined' ELSE [Unit Price] END [Unit Price],
A.Quantity,
A.Amount
FROM ( SELECT Id, Item, Unit,
CAST(MIN([Unit Price]) AS VARCHAR(20)) [Unit Price],
SUM(Quantity) Quantity, SUM(Amount) Amount
FROM YourTable
GROUP BY Id, Item, Unit) A
LEFT JOIN ( SELECT Id
FROM YourTable
GROUP BY Id
HAVING COUNT(DISTINCT [Unit Price]) > 1) B
ON A.Id = B.Id
Added an sql fiddle for you to try. (Credit to @bonCodigo, since I based my fiddle on the one he already had, but with my code).
This is the result:
ID ITEM UNIT PRICE QUANTITY AMOUNT
1 Gasoline L Undefined 90 539.9
2 Water Bottle 5.00 20 99.9
3 Meat Kg 14.90 15 223.5
4 Milk Can 7.45 30 223.5
回答2:
Try this code please,
select Id, item, unit, sum(quantity) totoal_Qt ,
sum(amount) total_Px from td
group by id, item, unit
;
Results:
ID ITEM UNIT TOTOAL_QT TOTAL_PX
1 Gasoline L 90 539.9
2 Water Bottle 10 50
3 Meat Kg 15 223.5
4 Milk Can 30 223.5
SQLFIDDLE
EDIT Using CASE
This is the closest I could get. It is a nice question. +1 for that. So the flaw with this editted answer that it will show you 'Undefined' for one item that has multiple unit_prices, however it will not show the unit_price even one items's multipel entries have the same unit_price. Answer is in full ANSI syntax.
*SQLFIDDLE
Changed the sample data to test for various scenarios.
ID ITEM UNIT UNIT_PRICE QUANTITY AMOUNT
1 Gasoline L 2 10 20
1 Gasoline L 2.5 20 50
2 Water Bottle 5 10 50
3 Meat Kg 14.9 15 223.5
1 Gasoline L 8 50 400
4 Milk Can 7.45 30 223.5
1 Gasoline L 6.99 10 69.9
2 Water Bottle 5 10 49.9
Query:
select distinct x.id, x.item, x.unit,
x.total_Qt, x.total_Amt,
case when x.unitPrice = 0
then 'Undefined'
else cast(y.unit_price as varchar(9))
end as UP
from(
select Id, item, unit, sum(quantity) total_Qt ,
sum(amount) total_Amt,
case when count(unit_price)>1
then 0
else 1
end unitPrice
from td
group by id, item, unit) as x
left join
(select distinct id, item, unit, unit_price
from td) as y
on x.id = y.id
and x.item = y.item
and x.unit = y.unit
;
Results:
ID ITEM UNIT TOTAL_QT TOTAL_AMT UP
1 Gasoline L 90 539.9 Undefined
2 Water Bottle 20 99.9 Undefined
3 Meat Kg 15 223.5 14.90
4 Milk Can 30 223.5 7.45
来源：https://stackoverflow.com/questions/14043162/how-to-query-data-from-sql-server