Find Duplicate Rows in SQL Server with a CTE

This tip demonstrates how find and list allf duplicate rows in a dataset using a Common Table Expression (CTE).

String Similarity I

Creating JSON III

Missing the Jaro Winkler Distance

Fun with JSON

Last year, I used a lot of JSON to exchange data between systems. There are several ways to extract data from a JSON file, but there is one specific, probably less-used possibility that I’d like to highlight. For one project, I received JSON files containing a variable number of parameters and their values. If I […]

Creating JSON II

The String Distance I

What's the Date?

Using REGEXP_COUNT to Count Strings in SQL Server 2025

We need to find out how many times certain strings appear in a column. We’ve used the LEN and REPLACE functions for years, but recently heard about REGEXP_COUNT and want to evaluate it, since we plan to upgrade to SQL Server 2025. How can we test this new feature?

How Filters and Sorting can Derail SQL Pagination Performance

In my previous tip, Pagination Performance in SQL Server, I showed how to make SQL pagination more predictable – turning O(n) into O(1). I materialized and cached row numbers to page through instead of calculating them on every request. It wasn’t the whole story, though; real pagination queries rarely get to sort without filtering. Users always want more control, and filtering can threaten that predictability.