A User-Defined Function returns more rows

The Problem Recently, while working with one of my clients, I came across a script in which I had to introduce a scalar User-Defined Function in the SELECT statement. The SELECT used to return around 750K records. However, after introducing the UDF, the row count significantly increased to 826K. There were no other changes made […]

SELECT with DISTINCT and TOP

Performance Surprises and Assumptions : GROUP BY vs. DISTINCT

Aaron Bertrand acknowledges that DISTINCT and GROUP BY are usually interchangeable, but shows there are cases where one performs better than the other.

COUNT, COALESCE, ISNULL, DISTINCT

Union Forcing Distinct

The use of union would seem to force a distinct in each of the select statements being unioned. The use multiple unions, with mixed union and union all clauses, seems to cause haphazard results.

Different ways to write Distinct Query - MSSQL

Distinct Query

SQL DISTINCT on Multiple Columns

Learn the basic usage of DISTINCT in this article.

Distincting an IN subquery

This is going to be a quick one…
I keep seeing forum code (and production code) that includes the DISTINCT in...

Question of the Day for 22 Jun 2005

Comments posted to this topic are about the Question of the Day for 22 Jun 2005 posted at http://qa.sqlservercentral.com/testcenter/qod.asp?QuestionID=535.

RE: My update triggers fired even no record is updated!

Thanks for your help.  But I still have problem with my 2nd trigger.The 2nd trigger will update the 1st table (set Update_Ind=1) when there's a update on 2nd table (UPR00200).  So I guess the join is not correct, join       dbo.UPR00100 UPR1 on UPR1.EmployID = UPR2.EmployID and UPR1.ADRSCODE = UPR2.ADRSCODEbut when I apply the changes […]