How to reset an identity field to the next contiguous value, after deletions.  Read more...

Splitting strings based on patterns supported by LIKE and PATINDEX can be an interesting way to address a wide variety of problems.  Read more...

One of the most common T-SQL questions is on returning a ranked result set for each member of a group. Dave Ballentyne brings us a short tutorial on how you can do this in T-SQL.  Read more...

This article explains how to use the GROUPING clause to generate subtotals for rows in a very easy fashion.  Read more...

In this sequel to his first "Hierarchies on Steroids" article, SQL Server MVP Jeff Moden shows us how to build a pre-aggregated table that will answer most of the questions that you could ask of a typical hierarchy. Any bets on whether Santa is packin’ a Tally Table in his bag or not?  Read more...

SQL Server MVP Jeff Moden shows us a new very high performance method to convert an "Adjacency List" to “Nested Sets” on a million node hierarchy in less than a minute and 100,000 nodes in just seconds. Not surprisingly, the "steroids" come in a bottle labeled "Tally Table".  Read more...

This article shows a clean non-looping method to parse comma separated values from a parameter passed to a stored procedure.  Read more...

A quick solution is a table function that will create a date range based on the parameters given. Then, you can just join to the results.  Read more...

This article contains a T-SQL script that can show you the dependency of all objects in your SQL Server database.  Read more...

Unless you are working on a reporting-only application you will probably need to update tables in your SQL Server database. To update rows in a table you use the UPDATE statement. In this level we will be discussing how to find and update records in your database, and discuss the pitfalls you might run into when using the UPDATE statement.   Read more...

This article will demonstrate a method of creating an Excel-based CPU/scheduler performance dashboard for SQL Server 2005+.  Read more...

Relational Datbases have tables as data structures, not arrays. This makes it tricky and slow to do matrix operations, but it doesn't mean it is impossible to do. Joe gives the Celko Slant on how to go about doing Matrix Math in SQL.  Read more...

In this article, we provide a simple way to get a comma delimited list from a table of entries without having to use a CURSOR or a WHILE loop to read through the table.  Read more...

You may have data in a database that was inserted into a table by mistake, or you may have data in your tables that is no longer of value. In either case, when you have unwanted data in a table you need a way to remove it. The DELETE statement can be used to eliminate data in a table that is no longer needed. In this article you will see the different ways to use the DELETE statement to identify and remove unwanted data from your SQL Server tables.  Read more...

Learn how an outer join works and how you can use it in your applications to find the results you need when matching data isn't in all your tables.  Read more...

This article from Todd Fifield shows a Way to avoid the dreaded LIKE operator in your queries and dramatically speed up keyword searches.  Read more...

Not all applications are limited to only retrieving data from a database. Your application might need to insert, update or delete data as well. In this article, I will be discussing various ways to insert data into a table using an INSERT statement.  Read more...

There are seven common antipatterns in T-SQL coding that make code perform badly, and three good habits which will generally ensure that your code runs fast. If you learn nothing else from this list of great advice from Grant, just keep in mind that you should 'write for the optimizer'.  Read more...

In this article I will be expanding on my discussion of the GROUP BY clause by exploring the ROLLUP, CUBE and GROUPING SETS operators. These additional GROUP BY operators make it is easy to have SQL Server create subtotals, grand totals, a superset of subtotals, as well as multiple aggregate groupings in a single SELECT statement.  Read more...

In a followup to his first article on Hierarchies, Gus Gwynn takes a look at the performance of a few different methods of querying a hierarchy. Learn how the HierarchyID stacks up.  Read more...