sqlglot VS dbt-unit-testing

This is probably referring to "zero changes to your driver code" and not "zero changes to the SQL you send over this driver".

Translating between SQL dialects is notoriously hard and attempts to translate [1] are working in 95% of cases. But the last 5% would require 5x amount of work. That's because "SQL dialect" also includes weird edge cases of type inference of things like COALESCE(5, FALSE) and emulation of system catalogs (pg_catalog, information_schema).

[1] https://github.com/tobymao/sqlglot

Recommend checking out https://github.com/tobymao/sqlglot if you are interested in this capability for other SQL dialects

Tools like this are helpful for:

- Rendering SQL in a consistent way, eg for snapshot testing

sqlglot – Python SQL Parser and Transpiler

In the project we used Python lib networkx and a DiGraph object (Direct Graph). To detect a table reference in a Query, we use sqlglot, a SQL parser (among other things) that works well with Bigquery.

Cool! Is this built with sqlglot[1] on the back end?

[1] https://github.com/tobymao/sqlglot

Wanted to give sqlglot a shoutout as it saved me a ton of time.

If you use dbt for transformations Dbt Unit Testing (https://github.com/EqualExperts/dbt-unit-testing) is getting some attention (https://www.thoughtworks.com/radar/languages-and-frameworks?blipid=202304042)

dbt-unit-testing

We use this and take an example-based tests approach for any non-trivial tables: https://github.com/EqualExperts/dbt-unit-testing

> How do you test some SQL logic in isolation?

I do this using sql

1. Extracting an 'ephemeral model' to different model file

2. Mock out this model in upstream model in unit tests https://github.com/EqualExperts/dbt-unit-testing

3. Write unit tests for this model.

This is not different than regular software development in a language like java.

I would argue its even better better because unit tests are always in tabular format and pretty easy to understand. Java unit tests on other hand are never read by devs in practice.

I haven't done it yet but there are some popular blogs as well as a DBT package someone created.

> I really don’t understand the communities obsession with unwieldy tools like DBT.

It lets me write test first sql transforms. I never thought TDD sql would be possible. My sql is so much more readable with common logic extracted into ephmeral models. I practice same method to write clear code to write sql, eg: too many mocks = refactor into separate model ( class) .

I think DBT made this possible with refs that can be swapped out with mocks. This is the awesome library I am using https://github.com/EqualExperts/dbt-unit-testing