SUM的多个不同值

Question

i have a table which Data is like

userID      name        amount   Date
     1        mark        20     22-10
     1        mark        30     22-10
     2        kane        50     22-12  
     2        kane        60     22-12
     3        mike        60     22-10 

Date is Unique with combination of userID + Username + Date

but as its more then 100k records there maybe duplicate date records but wither other user ids and names not with

now i want Output like

userID      name        amount    Date
     1        mark        50      22-10
     2        kane        110     22-12 
     3        mike        60      22-10

if i try group By with id,name,sum(amount),date it returns multiple rows and answer incorrect

i have tried various combination of distict and SUM etc etc but not succeeded any Solution Thanks

Answer 1

You typically use a GROUP BY to aggregate one or more fields by one or more other fields.

SELECT  userID, Name, SUM(amount), MIN(date)
FROM    YourTable
GROUP BY
        userID, Name

From MSDN: Aggregate functions

Aggregate functions perform a calculation on a set of values and return a single value. With the exception of COUNT, aggregate functions ignore null values. Aggregate functions are often used with the GROUP BY clause of the SELECT statement.

some typical aggregate functions are

• SUM
• MIN
• AVG
• ...

From MSDN: GROUP BY

Groups a selected set of rows into a set of summary rows by the values of one or more columns or expressions in SQL Server 2008 R2. One row is returned for each group. Aggregate functions in the SELECT clause list provide information about each group instead of individual rows.

Answer 2

select 
  userId, name, sum(amount) as amount
from
  table
group by
  userId, name

Answer 3

You don't want DISTINCT here, but rather GROUP BY with the aggregate SUM()

SELECT 
  userID,
  name,
  SUM(amount) AS amount
FROM tbl
GROUP BY userID, name