Question

I have a query that returns a single row of data. Let’s say it looks like this (with column headers).

Fruit    | Veg     | Meats   | Nuts    |
----------------------------------------
Apple      Lettuce   Veal      Almond

Instead of this, I’d like to return this single row as a two column table, with the column/field name in the leftmost column. Like so:

FieldName  | Value    |
-----------------------
Fruit        Apple
Veg          Lettuce
Meats        Veal
Nuts         Almond

Seems like there should be some non-painful way to make this happen, but if there is I can’t seem to find it. Hit a brick wall. Is this even possible?

Thanks much for any input.

EDIT: The query returns results that aren’t static, so I won’t be able to explicitly define the column headings.

EDIT 2: I’m trying to get some of these suggestions to work, and still can’t get this to function with more than one column. Here’s my code:

SELECT
  TOP 10
  FieldName,
  CAST(FieldValue as varchar(MAX)) As FieldValue
FROM Meter M
UNPIVOT([FieldValue] FOR FieldName IN ([MeterName],[MID])) UP
WHERE ClientNumber = 12300

Every time, I get the error “Msg 8167, Level 16, State 1, Line 4
The type of column “MID” conflicts with the type of other columns specified in the UNPIVOT list.”

I’ve looked this up, and it appears to be an issue related to column types/length, and no matter how I cast the FieldValue, same error. Any thoughts there?

EDIT 3: Resolution to the column conflict…

Casting results from the original table would NOT work, so I had to use a derived table and cast there so that the columns being returned to the PIVOT were all the same data type. Odd, but the only solution I could find that would run.

SELECT
  FieldName,
  CAST(FieldValue as varchar(MAX)) As FieldValue,
FROM 
(
  /* 
  Derived table so that we can control the column
  types for everything selected, because PIVOT demands
  that every pivoted column be of the same data type and
  length.
  */
  SELECT
    TOP 1
    CAST(M.MeterName as varchar(MAX)) As MeterName,
    CAST(M.MID as varchar(MAX)) As MID,
    CAST(D.DeviceType as varchar(MAX)) As DeviceType
  FROM Meter M
    INNER JOIN CurrentDevice D ON
      D.ClientNumber = M.ClientNumber AND
      D.MID = M.MID
  WHERE 
    M.ClientNumber = 12300
) T
UNPIVOT([FieldValue] FOR FieldName IN ([MeterName],[MID],[DeviceType])) UP

Answer 1

For SQL Server 2005+ you can use UNPIVOT:

SELECT FieldName, Value
FROM YourTable T
UNPIVOT([Value] FOR FieldName IN (Fruit, Veg, Meats, Nuts)) UP

Here is an SQL Fiddle for you to try.

Updated for new requirement

Ok, so you need dynamic SQL if you don’t know the columns of your table. First, go to this link. Then you can try the follwing:

DECLARE @Fields NVARCHAR(MAX), @Sql NVARCHAR(MAX)

SELECT @Fields = STUFF((SELECT DISTINCT ',' + QUOTENAME(Name) 
                        FROM sys.columns
                        WHERE OBJECT_ID = OBJECT_ID('YourTable')
                        FOR XML PATH('')),1,1,'')


SET @Sql = '
SELECT FieldName, Value
FROM YourTable T
UNPIVOT([Value] FOR FieldName IN ('+@Fields+')) UP
'

EXEC sp_executesql @sql