From the course: SQL Server 2008 Essential Training

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Creating user-defined functions

Creating user-defined functions - SQL Server Tutorial

From the course: SQL Server 2008 Essential Training

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Creating user-defined functions

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Not only do you have the over 200 functions defined in SQL Server, you can also define your own, what are referred to as user-defined functions, sometimes abbreviated to UDFs. So let's say I've got a piece of SQL here which is doing a sub-query and what this is doing right now is finding the company name for the customer who has placed the largest order. Okay, it's a simple example but this should do the trick. Let's imagine that I want to get this page of information 25 times a day. So I'd like a function that returns it. Well I can start off with this SQL that I have, but I do need to provide a few more pieces of information for me to describe what this function is and for a start, I am going to have to give it some kind of name. Now functions often take parameters. So I do have to tell SQL Server does this one have any parameters or does it have no parameters. And then I've also got to say what is returned by the function. So most of what I am going to have to write is actually…

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