Support decimal.Decimal type

Decimal types in Postgres cause a failure in db.py data type selection

I have a Django app using a MoneyField, which uses a numeric(14,0) data type in Postgres (https://www.postgresql.org/docs/9.3/datatype-numeric.html). When attempting to export that table I get the following error:

$ db-to-sqlite --table isaweb_proposal "postgres://connection" test.db
....
    column_type=COLUMN_TYPE_MAPPING[column_type],
KeyError: <class 'decimal.Decimal'>

Looking at sql_utils.db.py at 292-ish it’s clear that there is no matching type for what I assume SQLAlchemy interprets as Python decimal.Decimal.

From the SQLite docs it looks like DECIMAL in other DBs are considered numeric.

I’m not quite sure if it’s as simple as adding a data type to that list or if there are repercussions beyond it.

Thanks for a great tool!

[simonw]

Released in 2.9 https://sqlite-utils.readthedocs.io/en/latest/changelog.html#v2-9

[simonw]

I’m going to set it up so that Python decimal.Decimal is treated in a FLOAT column, until someone convinces me otherwise!