SQL Design Patterns (2010)

I always tell people to worry about the data structures that you want the database to maintain for you, and not worry about the SQL. You can always use Google to look up the SQL, or now ChatGPT to generate it for you. SQL is a not-that-great language and it intentionally hides what's going on. It is also different enough between databases that you need to pay attention. So learning to design/think in terms of SQL is probably not worth doing.

The set of data structures that you use to model and index a dataset is worth understanding, and designing in that space is a skill worth learning.

Frankly, this is terrible advice. If you’re not designing your data model around the language it’s going to be queried in, how do you expect to get decent performance out of the database?

Also, in no way does SQL hide anything - it’s a declarative language, and will produce exactly what you tell it to, provided you understand what it is you asked it to do. The query engine is somewhat of a black box, but that is completely orthogonal.

> Also, in no way does SQL hide anything - it’s a declarative language, and will produce exactly what you tell it to.

Ha ha, no, SQL implementations can conform to the standard in unexpected ways.

NULL = NULL

Is that true or false? We didn't know until 2003.

https://en.wikipedia.org/wiki/Null_(SQL)#Criticisms