Dynamic pivot: sum of sales per month

Question

My table is like this:

Sitecode    Month  Amount
--------    -----  ------
XX          Jan     1000
XX          Jan     3000
XX          Apr     3000
XX          Apr     1000

What I want is, to show the result something like this:

Sitecode    MonthJAN   MonthAPR
--------    --------   --------
XX          4000       4000

Answer 1

As others have said this is known as a PIVOT. There are several ways in which you can transform your data from rows into columns of data.

If you know the values ahead of time, then you can hard-code the values. Prior to the PIVOT function you would use an aggregate function with a CASE statement.

Aggregate/CASE Version:

select sitecode,
  sum(case when [month] = 'Jan' then amount else 0 end) MonthJan,
  sum(case when [month] = 'Apr' then amount else 0 end) MonthApr
from yourtable
group by sitecode;

See SQL Fiddle with Demo.

The PIVOT function was made available in SQL Server 2005, so if you are using that version or a newer one then you can apply that to your data.

Static PIVOT:

select *
from
(
  select sitecode,
    [month],
    amount
  from yourtable
) src
pivot
(
  sum(amount)
  for month in (Jan, Apr)
) piv;

See SQL Fiddle with Demo

The above two versions work great if you know the values ahead of time. If not, then you will use dynamic sql to create the result.

Dynamic PIVOT:

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT distinct ',' + QUOTENAME(month) 
                    from yourtable
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')

set @query = 'SELECT sitecode,' + @cols + ' from 
             (
                select sitecode, [month], amount
                from yourtable
            ) x
            pivot 
            (
                sum(amount)
                for month in (' + @cols + ')
            ) p '

execute(@query)

See SQL Fiddle with Demo

All 3 versions of this will return the same result:

| SITECODE |  JAN |  APR |
--------------------------
|       XX | 4000 | 4000 |

Answer 2

As Martin Smith said, you need to pivot the data, whether with an explicit PIVOT as referenced or something like this (SQL Fiddle):

SELECT SiteCode
   , SUM(Case When Month='Jan' Then Amount Else 0 End) MonthJan
   , SUM(Case When Month='Apr' Then Amount Else 0 End) MonthApr
FROM Result GROUP BY SiteCode;