Support connections to DuckDB for data-diff --dbt

[dbeatty10]

resolves #21

Overview

This PR probably isn't the long-term solution that you want. But it was a quick-n-easy way for me to get moving again for this demo.

Totally fine with me if you want to fix the problem below a different way!

Details

I was trying to run the following command when using a custom fork that added support for duckdb connections:

data-diff --dbt

But I got the following error:

ERROR - DuckDB: Bad table path for <data_diff.databases.duckdb.DuckDB object at 0x10b67f5e0>: 'main.dev.simple_model'. Expected form: schema.table

Since I wasn't super interested in discovering why this was happening or how best to solve it, this PR represents my quickest solution to the problem.

Here's the full stack trace:

Traceback (most recent call last):
  File "/Users/dbeatty/projects/data-diff/env/bin/data-diff", line 8, in <module>
    sys.exit(main())
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/click/core.py", line 1130, in __call__
    return self.main(*args, **kwargs)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/click/core.py", line 1055, in main
    rv = self.invoke(ctx)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/click/core.py", line 1404, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/click/core.py", line 760, in invoke
    return __callback(*args, **kwargs)
  File "/Users/dbeatty/projects/data-diff/data_diff/__main__.py", line 267, in main
    dbt_diff(
  File "/Users/dbeatty/projects/data-diff/data_diff/dbt.py", line 76, in dbt_diff
    _local_diff(diff_vars)
  File "/Users/dbeatty/projects/data-diff/data_diff/dbt.py", line 124, in _local_diff
    table1_columns = list(table1.get_schema())
  File "/Users/dbeatty/projects/data-diff/data_diff/table_segment.py", line 85, in get_schema
    return self.database.query_table_schema(self.table_path)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/sqeleton/databases/base.py", line 389, in query_table_schema
    rows = self.query(self.select_table_schema(path), list)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/sqeleton/databases/base.py", line 380, in select_table_schema
    schema, name = self._normalize_table_path(path)
  File "/Users/dbeatty/projects/data-diff/env/lib/python3.9/site-packages/sqeleton/databases/base.py", line 488, in _normalize_table_path
    raise ValueError(f"{self.name}: Bad table path for {self}: '{'.'.join(path)}'. Expected form: schema.table")
ValueError: DuckDB: Bad table path for <data_diff.databases.duckdb.DuckDB object at 0x10b67f5e0>: 'main.dev.simple_model'. Expected form: schema.table

[erezsh]

We are interested in fixing things the proper way. Quick and easy for you means strange and confusing bugs for others.

The question to ask is why would dbt return a 3-part path when duckdb supports only 2 parts.

If we're going to truncate the path at all, it's going to be inside dbt.py and not duckdb.py.

Also, whatever fix we land on, I think it should just be included in PR #408 so I'm closing this one.