I have an sql query \"Select * from tablename\" whose output is
col1 col2
A 1
B 2
C 3
I want to modify the ab
You will need to perform a PIVOT. There are two ways to do this with PIVOT, either a Static Pivot where you code the columns to transform or a Dynamic Pivot which determines the columns at execution.
Static Pivot:
SELECT *
FROM
(
SELECT col1, col2
FROM yourTable
) x
PIVOT
(
min(col2)
for col1 in ([A], [B], [C])
)p
See SQL Fiddle with Demo
Dynamic Pivot:
DECLARE @cols AS NVARCHAR(MAX),
@query AS NVARCHAR(MAX)
select @cols = STUFF((SELECT distinct ',' + QUOTENAME(col1)
from t1
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = 'SELECT ' + @cols + ' from
(
select col1, col2
from t1
) x
pivot
(
min(col2)
for col1 in (' + @cols + ')
) p '
execute(@query)
See SQL Fiddle with Demo
If you do not want to use the PIVOT
function, then you can perform a similar type of query with CASE
statements:
select
SUM(CASE WHEN col1 = 'A' THEN col2 END) as A,
SUM(CASE WHEN col1 = 'B' THEN col2 END) as B,
SUM(CASE WHEN col1 = 'C' THEN col2 END) as C
FROM t1
See SQL Fiddle with Demo
You want to use PIVOT
or COALESCE
in sql.Here is a nice examples how to converting rows to columns.
Five methods converting rows to columns
.