Misc sqldol stuff

[thorwhalen]

Random stuff.

[thorwhalen]

Layering with value transformers

The SqlBaseKvReader should be basic.
Even the one pointed to here could be more basic (for example, a layer of sql instructions, and a layer of their execution, before getting to the layer of "extraction" of the results that we have here).

The other desired interfaces (like getting a row as a {column_name: column_value, ...} dictionary, should be obtained via value transformation.

In sql.stores, I set up a few "value decoders", made store wrappers from them (with dol.wrap_kvs), and makde a few ready to use KvReaders (Mapping) with them, demoed here.
You can find these in the "Different value transformers" section of the sqldol_wip notebook.