add_column() should support REFERENCES {other_table}({other_column})

[simonw]

Related to #2

[simonw]

For the CLI I'm thinking:

sqlite-utils add-column data.db mytable col text --fk othertable id

So the foreign key is added using --fk othertable othercolumn

If the user doesn't provide the column type we can derive it from the foreign key.

Can we make the othercolumn optional? That would be neat - then we could automatically detect it using the sole primary key of the referenced table.

[simonw]

Hmm... probably not:

For options, only a fixed number of arguments is supported.

[simonw]

In that case --fk othertable detects the primary key.

If you want to point at a different column, use --fk-col X

[simonw]

Shipped this feature in sqlite-utils 1.1: https://sqlite-utils.readthedocs.io/en/latest/changelog.html#v1-1