My own aggregate function

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My own aggregate function

muk07

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December 8, 2003 at 11:33 pm

#160467

Is there any opportunity to write my own aggregate function, such as SUM,COUNT...
I asked this question yesterday but it has disappeared somewhere...

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Dinesh Asanka SSChampion Points: 11058 More actions · Answer 1

Yes

BOL

CREATE FUNCTION

Creates a user-defined function, which is a saved Transact-SQL routine that returns a value. User-defined functions cannot be used to perform a set of actions that modify the global database state. User-defined functions, like system functions, can be invoked from a query. They also can be executed through an EXECUTE statement like stored procedures.

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edwin_fredrick Old Hand Points: 364 More actions · Answer 2

I don't think you can create functions like SUM,Count with UDF.

Frank Kalis SSC Guru Points: 111183 More actions · Answer 3

Here is your first question and my reply

http://www.sqlservercentral.com/forum/link.asp?TOPIC_ID=18953

Frank

http://www.insidesql.de

http://www.familienzirkus.de

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Frank Kalis
Microsoft SQL Server MVP
Webmaster: http://www.insidesql.org/blogs
My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

muk07 SSC-Addicted Points: 417 More actions · Answer 4

quote:
Yes
BOL
CREATE FUNCTION
Creates a user-defined function, which is a saved Transact-SQL routine that returns a value. User-defined functions cannot be used to perform a set of actions that modify the global database state. User-defined functions, like system functions, can be invoked from a query. They also can be executed through an EXECUTE statement like stored procedures.

It's not a thing I asked

I want to write

select MyFunc(x) group by y

muk07 SSC-Addicted Points: 417 More actions · Answer 5

quote:
I don't think you can create functions like SUM,Count with UDF.

It seems me so, but may be some extended (C++) will help?

Frank Kalis SSC Guru Points: 111183 More actions · Answer 6

Writing your own extended procedure?

What difference should that make?

Frank

http://www.insidesql.de

http://www.familienzirkus.de

--
Frank Kalis
Microsoft SQL Server MVP
Webmaster: http://www.insidesql.org/blogs
My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

muk07 SSC-Addicted Points: 417 More actions · Answer 7

quote:
Writing your own extended procedure?
What difference should that make?
Frank
http://www.insidesql.de
http://www.familienzirkus.de

You ask questions instead of giving answers

Frank Kalis SSC Guru Points: 111183 More actions · Answer 8

Yes, I do.

With writing your own extended stored procedure you only extend to functionality of SQL Server, not the built-in functions.

I see no chance for you.

What aggregate function do you want to implement?

If this is for academical purposes, you might want to try to implement this into an open source db like http://www.mysql.com/maxdb

Frank

http://www.insidesql.de

http://www.familienzirkus.de

--
Frank Kalis
Microsoft SQL Server MVP
Webmaster: http://www.insidesql.org/blogs
My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

muk07 SSC-Addicted Points: 417 More actions · Answer 9

Thank you. When I asked this question I suspected that I have no chances, and knowing a litle about writing DBMS, supposed, that only way is to update DBMS source code. But I had a hope...

Frank Kalis SSC Guru Points: 111183 More actions · Answer 10

For this purposes I strongly suggest trying to follow open source code from mysql and/or maxdb. Not easy to get an entry point, but great way to look behind the scenes.

My best bet is that SQL Server or any other RDBMS handle things that are coded there not totally different.

Frank

http://www.insidesql.de

http://www.familienzirkus.de

Edited by - Frank kalis on 12/09/2003 03:45:48 AM

--
Frank Kalis
Microsoft SQL Server MVP
Webmaster: http://www.insidesql.org/blogs
My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

muk07 SSC-Addicted Points: 417 More actions · Answer 11

they say, that Yukon will allow such functions. Is it so?

Frank Kalis SSC Guru Points: 111183 More actions · Answer 12

I haven't dived too much into Yukon stuff yet, but as far as I understand some new features, you can write database code in some CLR language, pretty much as an alternative to T-SQL.

Still I don't think you can go down on this 'low level', but I'm not 100% sure on this and Yukon.

How would this comply with any SQL standard?

Frank

http://www.insidesql.de

http://www.familienzirkus.de

--
Frank Kalis
Microsoft SQL Server MVP
Webmaster: http://www.insidesql.org/blogs
My blog: http://www.insidesql.org/blogs/frankkalis/[/url]