sqlx

Go sqlx transaction recipe

This example uses github.com/jmoiron/sqlx, the Go library, not Rust SQLx. It uses the existing Workhorse NewSQLExecutor; it introduces no adapter package or SQL protocol.

Pinned baseline and execution

The maintained proof uses sqlx v1.4.0, pgx stdlib v5.11.0, Go 1.26.10, and local PostgreSQL 18.6. The dependency pins live in go/go.mod and go/go.sum. Applications install sqlx themselves; it is not required by Workhorse's core source.

Use a disposable PostgreSQL database with the Workhorse schema already installed. Apply the companion go/examples/sqlc/schema.sql business migration; both recipes use recipe_order for comparison. From a configured checkout:

WORKHORSE_DATABASE_URL="$DISPOSABLE_DATABASE_URL" pnpm exec tsx scripts/with-env.ts \
  go -C go run ./examples/sqlx
WORKHORSE_REQUIRE_DATABASE=1 pnpm exec tsx scripts/with-env.ts \
  go -C go test -count=1 -v ./examples/sqlx

The CLI writes a fixed UUID and prints its committed task UUID. Use a fresh schema for each repeat. The fixture creates and drops a dedicated scratch database and invokes the CLI too. The existing pnpm go:test discovers this fixture through ./...; there is no second integration CI suite.

Borrow the underlying transaction

database.BeginTxx returns a *sqlx.Tx containing the underlying *sql.Tx as tx.Tx. writeOrder uses tx.NamedExecContext for business SQL and NewQueue(NewSQLExecutor(tx.Tx), "recipes") for enqueue. sqlx may bind names in business queries. Do not pass Workhorse's SQL through Named, Rebind, or a formatter. The executor already sends PostgreSQL positional parameters through pgx stdlib.

The application owns commit, rollback, PostgreSQL savepoints, and database closure. sqlx supplies no nested transaction abstraction here; the fixture exercises explicit nested savepoints. Releasing a savepoint never commits the outer transaction. Keep the context used by BeginTxx alive until the transaction ends: database/sql rolls back if that context is cancelled. A separately cancelled in-flight statement can leave the transaction aborted or its connection unusable. Rollback with the owner and start a fresh transaction; do not promise savepoint recovery after driver cancellation.

The fixture proves physical PID/transaction identity, independent invisibility, joint outcomes, ownership, native JSONB/UUID/nullable values, batch order, structured SQLSTATE and typed Workhorse errors. It covers savepoint recovery after an ordinary SQL error, pre-cancelled calls, a blocked real enqueue's cancellation, fresh-transaction recovery, and application rollback on a client-side contract rejection.

Only pgx stdlib is tested. Other sqlx drivers, Rust SQLx, hosted providers, and poolers are outside this proof. Run a dedicated worker with its own pgx pool, never a request's *sql.Tx.

See the public Go sqlx appendix and transactional enqueue for the ownership contract.