Pivot table for Microsoft SQL Server

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Pivot table for Microsoft SQL Server

SwePeso

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May 31, 2006 at 10:25 am

#168660

Comments posted to this topic are about the content posted at http://www.sqlservercentral.com/columnists/plarsson/pivottableformicrosoftsqlserver.asp

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David Coster SSC Enthusiast Points: 118 More actions · Answer 1

Very nice! I will probably use this at some time. Thanks heaps!

Mike Dougherty Ten Centuries Points: 1112 More actions · Answer 2

Have you considered building the update string inside the loop, but executing it after you have iterated all the columns? O(1) < O(n)

Also, do you have any comments/caveats on the security implication of dynamic SQL used in this process?

RyanRandall SSChampion Points: 13623 More actions · Answer 3

Thanks Peter - nice looking article.

I've not read the whole article yet (that's for when I have more time), but I wonder how your approach compares with the 'classic' crosstab/pivot table approaches...

http://www.sqlteam.com/item.asp?ItemID=2955

http://weblogs.sqlteam.com/jeffs/archive/2005/05/02/4842.aspx

If anyone has time to evaluate this, I'd be very grateful!

Ryan Randall

Solutions are easy. Understanding the problem, now, that's the hard part.

SwePeso SSC-Dedicated Points: 39752 More actions · Answer 4

Yes, in my very first early version. Then I realized that I could potentially come across the 8000 character limit for varchars.

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SwePeso SSC-Dedicated Points: 39752 More actions · Answer 5

Thanks Ryan.

I have tried to keep the dynamic SQL executions to a minimum for obvious speed reasons. What I think I have provided is a base for creating crosstabs/pivots for users to learn from and hopefully, evolve with.

There are some things to do with the code to make it "universal". But I thought it would be best to show how to start from the beginning.

To make the code "universal" you first have to build a dynamic query for preaggregating the data in #Aggregates. That is not very hard to to! Also, you must change the parameters to the future stored procedure to allow two fully qualified names such as RemoteServer1.OwnerLocal.ThatTable.ThisField for the rows and columns. Even the CellData field in #Aggregates could be taken from a parameter this way and called with 'SUM(x)' or 'COUNT(y)'. You catch my drift.

An example could be

EXEC dbo.CrossTabPivot 'Table1.OfficeName', 'Table2.Category', 'COUNT(t)', ...

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SwePeso SSC-Dedicated Points: 39752 More actions · Answer 6

Yes, SQL injection could possible be an issue here, if the data in ColumnText is written such way.

But since the beginning of the UPDATE-statement is hardwired with "UPDATE", I right now can't see a way to manipulate the statement to run SQL injection code.

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teleMarinaV SSC Veteran Points: 246 More actions · Answer 7

I think it is worth mentioning the restrictions of that method such as:

- MAX number of columns (?),

- MAX total row length (8K).

I've used similar method using cursor instead of column table.

John Rempel SSCommitted Points: 1955 More actions · Answer 8

Perfect timing! I was able to use this logic for a report today. It made short work out of an otherwise arduous task.

Thanks.

SwePeso SSC-Dedicated Points: 39752 More actions · Answer 9

Max number of columns are restricted to what datatype you use for #Aggregate column. The total size for a row is 8,060 bytes. Using 60 bytes for RowText leaves us 8,000 bytes for the rest of the columns and since INT is 4 bytes, we can potentially have 2,000 columns. If you prefer SMALLINT (2 bytes) as #Aggregate column, you could theoretically have 4,000 columns.

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SwePeso SSC-Dedicated Points: 39752 More actions · Answer 10

You're welcome!

Now I have to look up "arduous" in my dictionary...

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R. M. Joseph Old Hand Points: 348 More actions · Answer 11

Thanks Peter. It is very good procedure and I shall use it.

R. M. Joseph

silvio costa SSC Enthusiast Points: 165 More actions · Answer 12

You got my Excellent! I've seen quite a few procedures, but I really appreciate your methodology: you paved a complete road from the ground up with concise and adequate explanations. I shall use it as a solid base for my pivot table reports. Thanks a lot.

Silvio E. Costa

SwePeso SSC-Dedicated Points: 39752 More actions · Answer 13

You are welcome!

I am satisfied you liked the article. I really struggled to keep it simple and consise. And as you write, my purpose was to give away the base of what pivot tables really are.

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Simeon Herbert SSC Journeyman Points: 81 More actions · Answer 14

Fantastic Article,

I now need to somehow work out to add ordering based on these "unknown" columns but this is a great start to stuff I really did not understand.

A Huge help - thanks.