I think you can learn SQL as SQL, without math background. OTOH just knowing mathematical model of SQL is not enough to write good SQL.
SQL in practice is not a purely mathematical construct: you have to know how to make use of spinning platters, indices, caches, locks, network connections, intricacies of data types and bunch of quirks and bugs of the RDBMS.
I've learned SQL before learning set theory properly. It turned out that I did understand (SQL-related parts of) it, I just didn't know it was called set theory :)
SQL in practice is not a purely mathematical construct: you have to know how to make use of spinning platters, indices, caches, locks, network connections, intricacies of data types and bunch of quirks and bugs of the RDBMS.
I've learned SQL before learning set theory properly. It turned out that I did understand (SQL-related parts of) it, I just didn't know it was called set theory :)