Ok fair enough. I suspect that's a pretty non-standard/rarely-used feature though. If you learn SQL you likely won't encounter this and I still contest the idea that SQL is a good entry into the logic paradigm.
SQL and Prolog are both relational. That's very unique to both. But SQL is all about querying databases. Prolog can also be used and understood as a database querying language but it's also very strong for
- parsers
- interpreters
- expert systems
- solving combinatorial problems
If you really want to you can probably use SQL for that too. Or any language for that matter. But going out and learning SQL won't naturally expose you to these applications and how well the logic paradigm lends itself to them.
SQL and Prolog are both relational. That's very unique to both. But SQL is all about querying databases. Prolog can also be used and understood as a database querying language but it's also very strong for
- parsers
- interpreters
- expert systems
- solving combinatorial problems
If you really want to you can probably use SQL for that too. Or any language for that matter. But going out and learning SQL won't naturally expose you to these applications and how well the logic paradigm lends itself to them.