[they4kman]

Just recently, I was putting some SQL into a PR description and wanted to keep implementation-specific details out of it. Specifically, I wanted to show a CHECK constraint. I figured I'd go see if they were in the SQL standard... and that was my first introduction to this absurdity.

The SQL standard is split into mine separate parts, each of which is purchased separately. The part I would've been interested in is part 2, which runs ~$220: https://www.iso.org/standard/63556.html

[gnufx]

Rather beside the point, but for people who aren't used to this, the usual dodges are first to search for the "final text" produced by the relevant standard committee (I have C and Fortran stashed, but I once got work to pay for the real C one). If that fails maybe consult the manual of a well-documented, high-quality implementation; that should tell you what versions(s) of the relevant standard(s) it supports and clearly mark extensions of the standard.