Monthly Archives: September 2009

Pivoting SQL Data

So, the other day I was trying to pivot some SQL data that was basically in this format…

RECNUMBERCOLNUMBERFIELDNAMEFIELDVALUE
11FirstNameDavin
12LastNameStuder
21FirstNameMelissa
22LastNameStuder

I wanted to see it like this …

RECNUMBERFIRSTNAMELASTNAME
1DavinStuder
2MelissaStuder

It took me a while to figure out the syntax for this, but here it is. It uses the SQL pivot keyword.

This first portion dynamically creates the column names to be used in the pivot.

declare @cols varchar(max)
 
select @cols = stuff (
    (
        select '], [' + FieldName
        from table
        group by FieldName
        order by min(ColNumber)
        for
        xml path('')
    ),
    1,
    2,
    ''
) + ']'

This next part creates a query within a string that we will run with the SQL exec command.

declare @query varchar(max)
 
set @query = '
    select RecNumber, ' + @cols + '
    from (
        select RecNumber, FieldName, FieldValue
        from table
    ) dta
    pivot
    (
        min(FieldValue)
        for FieldName in (' + @cols + ')
    ) pvt
'

All that is left to do is to execute the query that was created. I ended up putting this into a stored procedure.

exec(@query)