[b33j0r]

I didn’t “get” SQL for the first 6-8 years of professional full-stack engineering. I was chasing, along with many in my cohort, the ORM abstraction dragon we thought we needed to work on j2ee, django, or sqlalchemy teams quickly.

It’s perplexing to me now why SQL was perplexing. Even knowing about relational theory and enough DBA to pass interviews, it somehow always seemed like we should have been able to treat databases like our OOP’s.

To think of the hours I wasted. Maybe I heard in a meeting “it’s the join table” and another colleague said “just use the association table,” and I was trying the n^2 debugging approach to solve it with model classes.

The best advice I got on this made sense later: “I wouldn’t even try to manage that [dataset] myself. Just figure out how to tell a database to do it—that’s its only job.”

[bitwize]

Understanding relational algebra helps you write better SQL the way understanding lambda calculus helps you write better JavaScript. The language is warty and but a shadow of the pristine purity underneath, but it gets the job done and the theory guides your reasoning on how to use the language.

[lkuty]

In particular, I find the closure property of SQL very helpful and always think in terms of queries gettings tables and producing tables (derived most of the time). https://en.wikipedia.org/wiki/Closure_(mathematics)

[AdrianB1]

I really "got" SQL about 15 years after I started using it. The explanation is very simple: until that moment, SQL was a minor component for me in a big pie. Then one day I got into the position to troubleshoot some apps with >1 TB database behind them and I figured that SQL is more than simple CRUD operations. For most full stack developers that I know, SQL is still that minor component in the back of their mind and they are usually right.