Question

I have a query that gives me this result:

|SystemName    |SystemDescription   |CertificateType |CertName  |CertDate  |
----------------------------------------------------------------------------
| ABC          |Blah-blah ABC       | X             | X-865567  | 1 Jan    |
| ABC          |Blah-blah ABC       | Y             | Y-8a5567  | 2 Jan    |
| ABC          |Blah-blah ABC       | Z             | Z-86af67  | 3 Jan    |
| EFG          |Blah-blah EFG       | X             | X-8kuhkj  | 4 Jan    |
| EFG          |Blah-blah EFG       | Y             | Y-uiiou   | 5 Jan    |
| EFG          |Blah-blah EFG       | Z             | Z-8lkjhu  | 6 Jan    |
----------------------------------------------------------------------------

I need to produce this result:

|SystemName |SystemDescription   | X-Name  | X-Date | Y-Name | Y-Date | Z-Name | Z-Date|
---------------------------------------------------------------------------------------
|ABC        | Blah-blah ABC      |X-865567 | 1 Jan  |Y-8a5567| 2 Jan  |Z-86af67| 3 Jan |
|EFG        | Blah-blah EFG      |X-8kuhkj | 4 Jan  |Y-uiiou | 5 Jan  |Z-8lkjhu| 6 Jan |
----------------------------------------------------------------------------------------

In other words I need to pivot without aggregation and with at least 2 columns not pivoted.
Is it possible to produce this without functions, stored procedures and temp tables?? I know how to easily implement this with a few funcitons, I can come up with solution with temp table.

I wonder if it is possible to get a neat solution using PIVOT??

p.s. this is not a homework, just a brain-teaser -)

Answer 1

It is not necessary to use PIVOT to do this, sometimes it’s more of a mess to use it than it’s worth. As far as not using aggregate functions – think about it, you want to group your records in terms of SystemName and SystemDescription, you don’t have a choice but to use aggregates. That’s ok though, just use MAX as I have done, you’re going to get the results you want. The only thing you would need to worry about is in the scenario where there are two records with same SystemName, SystemDescription and CertificationType that have different values for CertName or CertDate – in that case you need some way to choose which attributes are selected for the group.

Here is a non-Pivot example:

SELECT SystemName,
       SystemDescription,
       MAX([x-Name]) AS [x-Name],
       MAX([x-Date]) AS [x-Date],
       MAX([y-Name]) AS [y-Name],
       MAX([y-Date]) AS [y-Date],    
       MAX([z-Name]) AS [z-Name],
       MAX([z-Date]) AS [z-Date]
FROM (
    SELECT SystemName, 
           SystemDescription,
           CASE CertificationType WHEN 'X' THEN CertName END AS [x-Name],
           CASE CertificationType WHEN 'Y' THEN CertName END AS [y-Name],
           CASE CertificationType WHEN 'Z' THEN CertName END AS [z-Name],
           CASE CertificationType WHEN 'X' THEN CertDate END AS [x-Date],
           CASE CertificationType WHEN 'Y' THEN CertDate END AS [y-Date],
           CASE CertificationType WHEN 'Z' THEN CertDate END AS [z-Date]
    FROM @yourTable
) T
GROUP BY SystemName, SystemDescription;