Clik here to view.
The T-SQL ROW_NUMBER() Function
If you learn one new T-SQL (i.e., Microsoft SQL Server) concept today it should be ROW_NUMBER(). Introduced in SQL 2005, this function is one of 4 window ranking functions (the others are RANK(),...
View ArticleClik here to view.
Common Table Expressions in SQL
In SQL Server 2005, Microsoft introduced the Common Table Expression (CTE). CTEs share similarities with VIEWS and derived tables, but are really not the same as either. Oracle SQL also supports CTEs...
View ArticleClik here to view.
Getting an INDEX SEEK to Speed up LIKE “%string%” Searches
In today’s blog I will attempt to challenge the popularly held notion that LIKE “%string%” wildcard searches must be slow (Sargability: Why %string% Is Slow). A Sample Table Populated with 10 Million...
View ArticleClik here to view.
Tally Tables in T-SQL
The Tally (or Numbers) table is one of the most useful constructs in intermediate-level SQL. Have you ever written a T-SQL WHILE loop? How about a CURSOR? If your answer to either of those questions is...
View ArticleClik here to view.
Calendar Tables in T-SQL
In an earlier blog, we covered a type of auxiliary table (the Tally Table) that can provide a lot of querying flexibility if you have one in your database or construct one in-line to your query. Today...
View ArticleClik here to view.
Make it Work, Make it Fast, Make it Pretty
When I first heard this, it struck me as being a remarkably concise wisdom applicable to virtually any programming task. The entire quotation is actually: “Make it work, make it fast, then make it...
View ArticleClik here to view.
Manipulating Dates and Times in T-SQL
In SQL 2008, Microsoft introduced some new date and time data types to augment the options available in prior versions. The full list of these data types with detailed explanations can be found in...
View ArticleClik here to view.
The One Million Row T-SQL Test Harness
So far in our blogs, we have talked a bit about performance, but today we’re going to show you a way you can confirm without doubt that you’re writing high-performance T-SQL code. This extremely...
View ArticleClik here to view.
Using the T-SQL MERGE Statement
In SQL Server 2008, Microsoft added a new SQL query type: the MERGE statement. This flexible query provides the ability to perform INSERTs, UPDATEs and even DELETEs all within a single statement. Used...
View ArticleClik here to view.
Stupid T-SQL Tricks – Part 1: Logarithms
Not just for math geeks, logarithms and their inverse functions (the exponentials) can have useful and often unexpected capabilities in T-SQL. “Heeeeeere’s Johnny!” – Ed McMahon introducing Johnny...
View ArticleClik here to view.
Lessons Learned from a Poor-performing VIEW
It is a “common knowledge” among SQL practitioners that VIEWs don’t perform well. Recently during an application’s development I put this to the test. I needed to construct a VIEW for a report the...
View ArticleClik here to view.
Stupid T-SQL Tricks – Part 2: Retrieving Columns Set to the Current DEFAULT...
“Heeeeeere’s Johnny!” – Ed McMahon introducing Johnny Carson for the Tonight Show If you’re old enough to remember the Tonight Show hosted by Johnny Carson, how can you not remember the iconic Stupid...
View ArticleClik here to view.
An Easter SQL
Since Easter is nearly upon us, I got to thinking once again about how challenging it is to calculate the day that Easter Sunday falls on. Since Calendar tables and their step-children Holiday tables...
View ArticleClik here to view.
An Even Faster Method of Calculating the Median on a Partitioned Heap
Back in 2013 I wrote an article kindly accepted for publication on the Simple Talk web site called Calculating the Median Value within a Partitioned Set Using T-SQL. In that article, I was delighted...
View ArticleClik here to view.
Stupid T-SQL Tricks – Part 3: A Zodiacal SQL
Today we’ll learn how you can use T-SQL to calculate your zodiac sign from your birthdate. “Heeeeeere’s Johnny!” – Ed McMahon introducing Johnny Carson for the Tonight Show If you’re old enough to...
View ArticleClik here to view.
Ruminations on Writing Great T-SQL
Today we’re going to try to extend some advice that I once heard from SQL MVP Jeff Moden, which I wrote about in my previous blog entitled “Make it Work, Make it Fast, Make it Pretty.” That advice was...
View ArticleClik here to view.
Excel in T-SQL Part 1 – HARMEAN, GEOMEAN and FREQUENCY
Today’s blog will be the first in a multi-part series on replicating Excel functions in T-SQL, starting with HARMEAN, GEOMEAN and FREQUENCY. We’ll focus our solutions on creating T-SQL in-line, Table...
View ArticleClik here to view.
Excel in T-SQL Part 2 – The Normal Distribution (NORM.DIST) Density Functions
Today’s blog will be the second in a multi-part series on replicating Excel functions in T-SQL, continuing with Excel’s NORM.DIST built-in function, thus enshrining my geekdom in the SQLverse forever....
View ArticleClik here to view.
The Best Tool for Comparing Whether Two T-SQL Queries Produce Identical Results
There is one software tool that should be in every software developer’s tool chest. That is knowledge of the platform on which you are developing. With all the hype that surrounds every new software...
View ArticleClik here to view.
High Performance T-SQL using Code Patterns
What exactly does this mean? We’ve heard of “code patterns” in other programming languages, but what does it mean to use T-SQL code patterns to develop high performance T-SQL? Having now been called...
View Article