Undo mix ash.codegen and mix ash.migrate?

Ash Forum Ash Questions / Help
,
1

How do you undo mix ash.codegen?

I added an attribute to my resource with allow_nil? false.

I ran mix ash.codegen add_entity_path and got resource_snapshots and migrations.

I get this error when running mix ash.migrate.

17:52:16.239 [info] alter table entities
** (Postgrex.Error) ERROR 23502 (not_null_violation) column "path" of relation "entities" contains null values

I tried changing allow_nil? true and ran mix ash.codegen add_entity_path_null, but I still get the same error.

Do I just delete the last two resource_snapshots and the migrations before running mix ash.codegen again?

2

I think this mistake comes from the Database. Basically you have at least 1 row in the DB where the attribute is has a nil value. You have to delete those records

3

Correct. You can, however if you want, undo the migrations as you described. We’re working on a tool for generating migrations that can be easily “undone” with mix ash.codegen --dev that tags the migrations as dev migrations. Then you can revert the dev migrations and delete them or you can “save” them with mix ash.codegen <a summary of all the changes>.

Until then, there is a script you can use to do it based off of the git changes:

2 Likes