2024-12-18
1,363 reads
User Defined Function (UDF)
2022-07-27
583 reads
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 […]
2019-10-14
5,001 reads
2008-05-20
4,224 reads
A Function Gotcha with the Use of an Asterisk
This article describes and demonstrates the problem of using asterisk to select all fields from a table within a table function. (from Apr 2008)
2009-09-11 (first published: 2008-04-30)
18,661 reads
UDF to return a multi column table of values from an input string
This UDF returns a multi column table of values from an input string of comma separated values
2008-06-11 (first published: 2008-04-29)
1,756 reads
2008-02-13 (first published: 2007-12-18)
1,723 reads
Understand when to use user-defined functions in SQL Server
In the simplest terms, a user-defined function (UDF) in SQL Server is a programming construct that accepts parameters, does work that typically makes use of the accepted parameters, and returns a type of result. This article will cover two types of UDFs: table-valued and scalar-valued.
2007-12-12
3,922 reads
Payment due date function
Calculates the nth due date for any given date, while accounting for weekends.
2012-05-16 (first published: 2007-10-11)
3,728 reads
Complex Computed Columns
Computed columns in SQL Server 2000 allow you to have a calculated value available easily in a query. However by using a function instead of a simple formula you can build some very interesting solutions. New author Tim Chapman brings us a look at this technique.
2006-05-09
21,438 reads
Blogs
SQL Server Time Bombs
By Kevin3NF
Common Reasons for Emergency SQL calls If you are a production DBA (or Accidental...
Book Review: A Radical Enterprise
By Steve Jones
I grabbed this book over the 2024 holiday season as it was on sale...
Advice I Like: Investing and Growing Rich
By Steve Jones
Investing small amounts of money over a long time works miracles, but no one...
Forums
What is time?
Comments posted to this topic are about the item What is time?
KB5046856 fails to install
Hello experts, The following SQL update is failing to install on some of our...
where to find information about xE sqlserver.databases_bulk_copy_throughput
where to find information about xE sqlserver.databases_bulk_copy_throughput ? I'm searching for de description of...
Question of the Day
Rows estimation with OPENJSON
Consider the following script for a Sql Server database with Compatibility Level at least 130 (Sql Server 2016):
create table tjson ( id int primary key, j1 varchar(max), j2 varchar(max), j3 varchar(max)); insert into tjson (id, j1, j2, j3) values (1, '[{"c11":"value11A", "c12":"value12A"},{"c11":"value11B", "c12":"value12B"}]', '[{"c21":"value21A", "c22":"value22A"},{"c21":"value21B", "c22":"value22B"}]', '[{"c31":"value31A", "c32":"value32A"},{"c31":"value31B", "c32":"value32B"}]');How many rows does the Query Optimizer estimate for the following query?
select id, c1.c11, c2.c21, c2.c22, c3.c31, c3.c32 from tjson cross apply openjson(j1) with( c11 varchar(50) '$.c11', c12 varchar(50) '$.c12') c1 cross apply openjson(j2) with( c21 varchar(50) '$.c21', c22 varchar(50) '$.c22') c2 cross apply openjson(j3) with( c31 varchar(50) '$.c31', c32 varchar(50) '$.c32') c3;See possible answers