“Thinking in sql” is hard because it’s an awkward syntax for the (much simpler) relational algebra.

Learn to think in terms of the relational algebra, and how to translate that to/from SQL, and it starts making sense.

I can express my ideas well enough in various Datalog/Prolog variants w/ the horn syntax. But when it comes to translating that from several discrete simple propositions into one massive CTE-stack SQL query I get very puzzled. I wrote a toy Datalog-to-SQLite compiler (https://percival.jake.tl) but I struggle to grasp the translation skill myself

I don't find that the syntax gets in the way of thinking in relational algebra, but I did learn SQL first.