Category: Syntax

Louis Davidson wraps up a series on regular expressions:

I am only combining them into a short version because they are, in how they work, very similar to all the other functions. I certainly will demonstrate all the functionality for each function, but not to the extra level I have in previous blogs.

This time, I will cover:

• REGEXP_INSTR Returns the starting or ending position of the matched substring, depending on the option supplied.
• REGEXP_COUNT Returns a count of the number of times that regex pattern occurs in a string.

Read on to see how these work in SQL Server 2025.

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Louis Davidson continues a series on regular expressions:

The REGEXP_SUBSTR function extracts parts of a string based on a regular expression pattern. It has some similarieties with the SUBSTRING function, but with some important (and interesting) differences. This function returns Nth occurrence of a substring that matches the regex pattern.

Read on to see how it compares to the traditional SUBSTRING() function.

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Steve Jones gins up a demo:

I saw this as a question submitted at SQL Server Central, and wasn’t sure it was correct, but when I checked, I was surprised. If you choose to designate columns as sparse, but you have a lot of data, you can use more space.

This post looks at how things are stored and the impact if much of your data isn’t null.

I consider sparse columns a relic of the mid-aughts era, when storage was a lot more expensive and compression was an Enterprise Edition-only feature. Given that you can use page compression in any edition of SQL Server nowadays, I don’t think there’s a viable reason ever to have a sparse column.

Also, definitely check out the comments, where Jeff Moden has a great one.

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Louis Davidson creates a table:

Continuing on with the REGEXP_ functions series, the next one I want to cover is the table valued function REGEXP_SPLIT_TO_TABLE. This function is definitely one of the ones you probably ought to know, especially if you are ever tasked to pull some data out of a data structure.

This function is a lot like the STRING_SPLIT function, and unlike things like the REGEXP_LIKE function, you can basically use the same main parameters as you used in STRING_SPLIT for simple cases, but from there the possibilities are a lot more endless because you can define almost any delimiters you want. It isn’t perfect, because of a few things, but we will discuss that more later on.

Read on to see how it works, including one major caveat.

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Louis Davidson continues a series on regular expressions in SQL Server 2025:

Okay, we have gone through as much of the RegEx filtering as I think is a a part of the SQL Server 2025 implementation. Now it is time to focus on the functions that are not REGEXP_LIKE. We have already talked about REGEXP_MATCHES, which will come in handy for the rest of the series.

I will start with REGEXP_REPLACE, which is like the typical SQL REPLACE function. But instead of replacing based on a static delimiter, it can be used to replace multiple (or a specific) value that matches the RegEx expression. All of my examples for this entry will simply use a variable with a value we are working on, so no need to create or load any objects.

Read on to see how it works, including plenty of examples.

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