protoc-gen-ratel

Protoc plugin that generates Ratel table definitions from .proto files.

Installation

go install github.com/yaroher/ratel/cmd/protoc-gen-ratel@latest

Usage

protoc \
  --go_out=. --go_opt=paths=source_relative \
  --plain_out=. --plain_opt=paths=source_relative \
  --ratel_out=. --ratel_opt=paths=source_relative \
  schema.proto

Prerequisites

You also need:

• protoc-gen-go — standard Go protobuf generator
• protoc-gen-plain — plain Go struct generator (no protobuf runtime)

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
go install github.com/yaroher/protoc-gen-go-plain/cmd/protoc-gen-plain@latest

Generated Files

For schema.proto, the plugin generates schema_ratel.pb.go containing:

• Table alias types and constants
• Column alias types and constants
• Scanner struct with GetTarget, GetSetter, GetValue
• Table struct with typed column fields
• Global table variable with full configuration
• Relation definitions and loaders

Proto Annotations

The plugin reads ratel.table, ratel.column, and ratel.relation options from your .proto files. See Proto Options for the full reference.

Example

schema.proto

syntax = "proto3";
package myapp;
option go_package = "myapp/models";

import "ratelproto/ratelproto.proto";

message User {
  option (ratel.table) = {
    generate: true
    table_name: "users"
  };

  int64 id = 1 [(ratel.column) = {
    constraints: { primary_key: true }
  }];
  string email = 2;
  string name = 3;
}

Run protoc:

protoc --go_out=. --plain_out=. --ratel_out=. schema.proto

Use the generated code:

users, err := models.Users.Query(ctx, db,
    models.Users.SelectAll().
        Where(models.Users.Email.Eq("john@example.com")),
)