I know a lot (a lot) of non-technical SQL users. SQL is a widespread abstraction from the underlying databases. It's very powerful. What you describe is useful

I know a lot (a lot) of non-technical SQL users. SQL is a widespread abstraction from the underlying databases. It's very powerful. What you describe is useful from a programmer's point of view, but maybe the wrong abstraction. You could write such a thing which actually generates SQL from an API like you've defined. You could write an alternate ODBC engine. But there is a lot of overhead for database authours to actually provide an API like you describe. It's far simpler to provide something SQL-compliant with an ODBC or JDBC driver and now you can plug in almost anywhere. I have used a database engine that exposes primitives to build filters and similar programs to what you describe, and selectively push them to the server. It's not a very deep abstraction.