SQL Server 2008中的求和函数

Question

I have a table:

 PropertyID     Amount        
 --------------------------
   1              40                   
   1              20                
   1              10                    
   2              10                 
   2              90            

I would like to achieve :

    PropertyId       Amount   Total_Amount
  ---------------------------------------       
      1                40        70
      1                20        70
      1                10        70
      2                10        100
      2                90        100

using below query :

SELECT  
    PropertyID,
    SUM(Amount),
    SUM(TotalAmount)
FROM 
    yourTable
WHERE 
    EndDate IS NULL
GROUP BY 
    PropertyID

Output:

    PropertyId       Amount   TotalAmount
  -------------------------------------       
      1                70      70
      2                100     100

Let me know how can I get my desired output ...

Answer 1

You can do this using window functions:

select PropertyID, Amount,
       sum(Amount) over (partition by PropertyId) as TotalAmount
from yourtable;

The window function for sum() does the following. It calculates the sum of amount for groups of rows in the same group. The group is defined by the partition by clause, so rows with the same value of PropertyId are in the same group.

Answer 2

SELECT  PropertyID,
    Amount,
    (select sum(yt.Amount)
      from yourTable yt where yt.PropertyID==y.PropertyID and yt.EndDate IS NULL)
    as TotalAmount
    FROM yourTable y
    WHERE y.EndDate IS NULL