Query Languages

There is of course sql .. and

PRQL – Pipelined Relational Query Language, pronounced “Prequel”. The web page has good examples and the advantages; probably the most promising looking of these query languages I have known so far (aug 2023).

And there is hydromatic/morel: Standard ML interpreter, with relational extensions, implemented in Java .. the reasoning behind the creation of Morel is given here – Morel: A functional language for data | Julian Hyde on Streaming Data, Open Source OLAP. And stuff. . The creator of Morel is also behind Apache Calcite, Mondrian (OLAP tool, IIRC).