I fail to see why one can't manipulate parsed SQL's AST. I think that this is the "every problem in CS can be solved by another layer of indirection" part. You

I fail to see why one can't manipulate parsed SQL's AST. I think that this is the "every problem in CS can be solved by another layer of indirection" part. You're basically sidestepping the issue of SQL not providing the functionality in the first place.