Visualizing SQL | Voice of the DBA

While I think SQL is interesting, I know some people struggle with the way the language work. Someone at work posted a link to this site: https://animatesql.com/

I think the idea is this site helps you visualize how a SQL query works. It’s not free form, and I can’t just write any SQL, but you choose a keyword and then a sample query is shown. If you press Visualize, it walks through how this query is processed.

Below, I choose the WHERE keyword and then pressed visualize. The sample query had a NOT before the parenthesis, which I removed.

The animation then works through each row, showing whether it fits the criteria. Here I have captured what things look like in the middle:

Eventually this goes through the process again with the SELECT part of the query and pulls results from the yellow rows, according to the columns listed in the query.

If you try the different keywords, you see different visuals and queries. You can modify them slightly, and the comments in the query window let you know what you change. The modifications are small, but they do let you see how well things work in different ways, such as if you change the value or remove a logical operator, as I did.

As I tried a few different items, it made sense to me, but I wonder if it would for someone that was learning. I think that this ought to have some explanation of what is happening (i.e. comparing the name and rating in each row to be null or not, and matching the criteria). For the GROUP BY, I really think someone might not understand what they are seeing without some explanation.

I also think the lack of NULL in the data, and showing a blank, is highly misleading as well.

This looks like something a developer built, and I think it is creative and helpful, but like many 1.0 things, this needs some evolution and improvement.

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