go-ruby-activerecord documentation

Rails' ActiveRecord ORM core in pure Go — SQL generation, associations and validations, no cgo.

go-ruby-activerecord/activerecord is a faithful, pure-Go (zero cgo) reimplementation of the deterministic core of Rails' ActiveRecord ORM, matching the real activerecord gem byte-for-byte. The module path is github.com/go-ruby-activerecord/activerecord.

It turns a model plus a relation description into SQL and runs validations, exactly as MRI's activerecord gem does — while the one thing that genuinely needs a database, executing the SQL, is an injected Adapter host seam (wired to go-ruby-sqlite3 / go-ruby-pg). So the module stays 100% Ruby- and CGO-free, and is both the ORM backend bound into go-embedded-ruby by rbgo — a sibling of go-ruby-sequel whose dialect approach it shares — and a standalone, reusable module.

Status: complete — MRI byte-exact

Faithful port of ActiveRecord's SQL generation and validations: a lazy, chainable Relation rendered by ToSQL, aggregate and DML builders, associations (belongs_to / has_many / has_one / HABTM / :through) emitting ActiveRecord's exact join geometry, schema DDL, validations producing an ActiveModel::Errors-shaped Errors, attributes with dirty tracking, and three dialects (SQLite / PostgreSQL / MySQL). Validated by a differential oracle against the real activerecord gem — generated SQL, errors.full_messages and DDL compared byte-for-byte — at 100% coverage, gofmt + go vet clean, CI green across the six 64-bit Go targets and three OSes.

Quick taste

rel := users.
    Where(map[string]any{"age": &ar.Range{Begin: 18, End: 30}}).
    Joins("posts").
    Order(map[string]any{"name": "asc"}).
    Limit(10)

fmt.Println(rel.ToSQL())
// SELECT "users".* FROM "users"
//   INNER JOIN "posts" ON "posts"."user_id" = "users"."id"
//   WHERE "users"."age" BETWEEN 18 AND 30
//   ORDER BY "users"."name" ASC LIMIT 10

Repositories

Repo	What it is
activerecord	the library — Rails' ActiveRecord ORM core in pure Go
docs	this documentation site (MkDocs Material, versioned with mike)
go-ruby-activerecord.github.io	the organization landing page (Hugo)
brand	logo and brand assets

Principles

• Pure Go, CGO_ENABLED=0 — trivial cross-compilation, a single static binary, no C toolchain; SQL execution is injected through an Adapter seam.
• MRI byte-exact. Generated SQL, errors.full_messages and schema DDL match the real activerecord gem exactly, validated by a differential oracle against ActiveRecord's own Relation#to_sql.
• Standalone & reusable. The ORM backend bound into rbgo, and importable by any Go program; the dependency runs that way, not the reverse.
• 100% test coverage is the target, enforced as a CI gate, across 6 arches and 3 OSes.

Where to go next

• Why pure Go — why this slice of ActiveRecord is deterministic enough to live as a standalone, database-independent Go library.
• Usage & API — the public surface and worked examples.
• Roadmap — what is done and what is downstream by design.

Source lives at github.com/go-ruby-activerecord/activerecord.