alextanhongpin / go-repository-test

Sample code structure for repository

go-repository-test

• always handle between db and tx in the usecase layer
• the tables (or storage, or any other relevant name to your liking) represents the mapping between the schema in the db to the golang code
• each usecase will have one repository
• this makes mocking easier, instead of having multiple repositories that is actually calling one table, this structure places the table mapping in the tables layer, and the repository layer acts as a facade that calls different tables
• note that the repository layer can also
  • call other third-party client apis
  • do caching transparently (e.g. check data exists in cache, otherwise query db results and cache them before returning)
  • maps table-specific or external data types to domain types (this is very important)
• migrations can be versioned, or done declaratively
  • using atlas as the tool, this does not have the concept of rollback migration
  • edit tables in schemas, and run make atlas-diff-apply to update the db state
  • for some usecases however, atlas cannot diff the changes
  • so for extensions, triggers and other dlls, we run manual migration
  • always run manual migration before declarative migration

Running migration

With Atlas (note: this is not ideal, use dbmate instead):

# Run versioned migrations (triggers, extensions, seeding data).
$ make atlas-migrate

# Run declarative migrations (schema changes).
$ make atlas-diff-apply

# Note that due to the sequence on migrations, the diff may have dependencies on extensions etc, so we need to re-run this again. Some triggers can only be created once the tables are created too.
# One alternative is to put the basic table creation in the versioned migration too and adding the trigger there.
$ make atlas-migrate

With dbmate:

$ make sql name=create_table...
$ make migrate
$ make rollback
$ make reset

Other migration options

declarative:

• migra for postgres, example here and here
• skeema for mysql
• dbmate

Postgres conf

Configuring non-durable settings. This is useful for speeding up tests.

https://www.postgresql.org/docs/current/non-durability.html

    command: postgres -c fsync=off -c synchronous_commit=off -c full_page_writes=off

show fsync;
show synchronous_commit;
show full_page_writes;