sqlc-gen-go

A sqlc plugin that generates type-safe Go database access code from SQL. Runs as a WASM plugin (recommended) or standalone binary.

Usage

version: '2'
plugins:
- name: golang
  wasm:
    url: https://github.com/vtuanjs/sqlc-gen-go/releases/download/v1.7.0/sqlc-gen-go.wasm
    sha256: 996233111f91edd925266b9c52645b581fe8d16e751c412d9a59179b70f3cb90
sql:
- schema: schema.sql
  queries: query.sql
  engine: postgresql
  codegen:
  - plugin: golang
    out: db
    options:
      package: db
      sql_package: pgx/v5

Building from source

make all  # produces bin/sqlc-gen-go and bin/sqlc-gen-go.wasm

To use a local build:

plugins:
- name: golang
  wasm:
    url: file:///path/to/bin/sqlc-gen-go.wasm
    sha256: ""  # optional since sqlc v1.24.0

Migrating from sqlc's built-in Go codegen

Two changes are required:

1. Add a top-level plugins entry pointing to the WASM plugin.
2. Replace gen.go with codegen, referencing the plugin by name. Move all options into the options block; out moves up one level.

Before:

sql:
- engine: postgresql
  gen:
    go:
      package: db
      out: db
      emit_json_tags: true

After:

plugins:
- name: golang
  wasm:
    url: https://github.com/vtuanjs/sqlc-gen-go/releases/download/v1.7.0/sqlc-gen-go.wasm
    sha256: 996233111f91edd925266b9c52645b581fe8d16e751c412d9a59179b70f3cb90
sql:
- engine: postgresql
  codegen:
  - plugin: golang
    out: db
    options:
      package: db
      emit_json_tags: true

Global overrides/go move to options/<plugin-name>:

options:
  golang:
    rename:
      id: "Identifier"
    overrides:
    - db_type: "timestamptz"
      nullable: true
      engine: postgresql
      go_type:
        import: "gopkg.in/guregu/null.v4"
        package: "null"
        type: "Time"

Advanced Options

emit_per_file_queries

Each SQL source file gets its own struct and interface instead of a shared Queries/Querier.

SQL file	Struct	Interface
users.sql	UsersQueries	UsersQuerier
user_orders.sql	UserOrdersQueries	UserOrdersQuerier

options:
  emit_interface: true
  emit_per_file_queries: true

• Each *.sql.go contains its own struct, constructor, methods, and interface.
• db.go only keeps DBTX; querier.go is not generated.
• Incompatible with emit_prepared_queries.

---

emit_err_nil_if_no_rows

:one queries return nil, nil instead of nil, sql.ErrNoRows when no row is found.

options:
  emit_err_nil_if_no_rows: true

---

emit_tracing

Injects custom code at the start of every query method. Supports {{.MethodName}} and {{.StructName}} template variables.

options:
  emit_tracing:
    import: "go.opentelemetry.io/otel"
    package: "otel"
    code:
      - "ctx, span := otel.Tracer(\"{{.StructName}}\").Start(ctx, \"{{.MethodName}}\")"
      - "defer span.End()"

Field	Description
import	Import path of the tracing package
package	Package alias (if different from the last path segment)
code	Lines to inject; each is a Go template

---

go_generate

Adds a //go:generate directive to each *.sql.go file. $GOFILE expands to the current filename at generate time.

options:
  go_generate: "mockgen -source=$GOFILE -destination=mock/$GOFILE -package=mock"

Running go generate ./... produces a mock per SQL file:

Source	Mock
users.sql.go	mock/users.sql.go
orders.sql.go	mock/orders.sql.go