March 1, 2025
After one of my recent posts, I was asked what an outer quantity was. This term is common in warehousing and logistics. So many business applications assume […]
February 28, 2025
One of the challenges with subqueries is they can get very, very messy if you need to use them more than once. So for example, in […]
February 27, 2025
Our free SDU Tools for developers and DBAs, now includes a very large number of tools, with procedures, functions, and views. I do a lot of […]
February 26, 2025
SQL Server 2008 and later support a VALUES clause. We can use this to construct a table on the fly. In the example above, you can […]
February 25, 2025
Our free SDU Tools for developers and DBAs, now includes a very large number of tools, with procedures, functions, and views. I do a lot of […]
February 24, 2025
In the previous T-SQL 101 post, I mentioned that some subqueries depend upon the outer query and others don’t. That’s the distinction between what are called […]
February 23, 2025
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around […]
February 22, 2025
Sometimes what we’re interested in is just whether or not a row exists. In the example shown, I’m saying I want to select product ID and […]
February 21, 2025
This is a post in the SQL Interview series. These aren’t trick or gotcha questions, they’re just questions designed to scope out a candidate’s knowledge around […]
February 20, 2025
Another way that we can use a subquery is in place of a list of values. I’ve previously shown how the IN operator allows us to […]
February 19, 2025
Our free SDU Tools for developers and DBAs, now includes a very large number of tools, with procedures, functions, and views. A request that I had […]
February 18, 2025
The first example of subqueries types in this series is what’s called a scalar subquery. In this case, I’m trying to work out which orders were […]