SQL, multiple rows to one column - sql

Question

So I have the following date
ID NAME MONTH COUNT
1 David December2012 500
2 Rob December2012 320
1 David January2013 400
2 Rob January2013 280
I am trying to make this.......
ID Name December2012 January2013
1 David 500 400
2 Rob 320 280
Where I get confused is how I want to keep two of the columns and just pivot the two other fields. Anyone know how I would do this.
Thank you so much for your help/time. I have never posted one of these, and responses are greatly appreciated!

Answer 1

You did not specify what RDBMS you are using. You can pivot the data in all databases using an aggregate function with a CASE expression:
select id, name,
sum(case when month = 'December2012' then "count" end) December2012,
sum(case when month = 'January2013' then "count" end) January2013
from yourtable
group by id, name
See SQL Fiddle with Demo
If you are using SQL Server 2005+ or Oracle 11g then you can use the PIVOT function:
select *
from
(
select id, name, month, [count]
from yourtable
) src
pivot
(
sum([count])
for month in (December2012, January2013)
) piv
See SQL Fiddle with Demo.
In SQL Server, if the values of the month are unknown then you can use dynamic SQL similar to this:
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 id, name,' + #cols + ' from
(
select id, name, month, [count]
from yourtable
) x
pivot
(
sum([count])
for month in (' + #cols + ')
) p '
execute(#query)
See SQL Fiddle with Demo
All versions yield the result:
| ID | NAME | DECEMBER2012 | JANUARY2013 |
-------------------------------------------
| 1 | David | 500 | 400 |
| 2 | Rob | 320 | 280 |

Answer 2

Since you didn't specify what RDBMS you are using, then you can do this:
SELECT
ID,
NAME,
MAX(CASE WHEN MONTH = 'December2012' THEN "COUNT" END) AS "December2012",
MAX(CASE WHEN MONTH = 'January2013' THEN "COUNT" END) AS "January2013"
FROM Tablename
GROUP BY ID, Name;