Database

Flamenco Manager and Worker use SQLite as database, and GORM as object-relational mapper (but see the note below).

Since SQLite has limited support for altering table schemas, migration requires copying old data to a temporary table with the new schema, then swap out the tables.

SQLC

Flamenco mostly uses GORM for interfacing with its SQLite database. This is gradually being phased out, to be replaced with SQLC.

Installing & using SQLC

SQLC can be installed (installation docs) with a go install command just like any other Go package, but that does depend on a C/C++ compiler:

go install github.com/sqlc-dev/sqlc/cmd/sqlc@latest

The precompiled sqlc binaries work just as well, so choose whatever works for you.

Installing sqlc itself is only necessary to regenerate the database code. Once generated, the code is independent of sqlc.

Since installing sqlc via go install requires a C/C++ compiler, it is not part of the make with-deps script. Because of this, it is also not included in the make generate-go script.

Handling Schema changes

Database schema changes are managed with Goose. Every change is defined in a separate SQL file, and has the queries to make the change and to roll it back. Of course the roll-back is only possible when no data was removed.

SQLC needs to know the final schema those Goose migrations produced. To generate the SQLC schema from the database itself, run:

make db-migrate-up
go run ./cmd/sqlc-export-schema

To generate Go code with SQLC after changing schema.sql or queries.sql:

go install github.com/sqlc-dev/sqlc/cmd/sqlc@latest
sqlc generate