使用分组依据更新临时表

Question

Getting this error

Msg 157, Level 15, State 1, Line 20
An aggregate may not appear in the set list of an UPDATE statement.

My UPDATE statement:

UPDATE #Results
SET CustomerName = dbo.GetCustomerNameByCustomerId(CustomerId),
    TotalIncremental = Sum(IncrementalDollarsDebitCredit),
    TotalDeficiency = 0
FROM 
    IncrementalCreditHeader ICH
INNER JOIN 
    IncrementalCreditHistory IC ON IC.IncrementalCreditID = ICH.IncrementalCreditID
WHERE
    IC.BillingPeriodStartDate < = '2015-07-01 00:00:00.000'
    AND ICH.ARCreatedFlag = 'Y' AND ICH.ActiveFlag = 1

Answer 1

in general, you can use the fact that you can update common table expressions in SQL server + apply the window function, like this:

create table temp (client_id int, amount int, total_amount int)

insert into temp (client_id, amount)
select 1, 10 union all
select 1, 15 union all
select 2, 5 union all
select 2, 7 union all
select 2, 15

;with cte as (
    select total_amount, sum(amount) over(partition by client_id) as new_total_amount
    from temp
)
update cte set
    total_amount = new_total_amount

--------------------------------
client_id   amount  total_amount
        1       10            25
        1       15            25
        2        5            27
        2        7            27
        2       15            27

sql fiddle demo

But in your question, you have to add #Results table to your update query otherwise it's not clear for SQL Server which rows to update