feat(M3): 只读 API 端点实现

- store: pgx 只读数据访问层(productByGTIN/ByID/search/nutriments/msrp/brands/categories/source)
- handler: 真实查询替换 501 占位, 统一分页 + 错误信封, MSRP 带免责声明无购买入口
- main: pgxpool 连接池接线
- search: 名称模糊 + 分类子树过滤(ltree <@)
- 测试: healthz/pageParams 单测 + DB-backed handler 集成测试(无库自动跳过)
- CI: Go job 增加 postgres service + migrate up, 实跑 DB 测试
- 依赖: pgx v5.7.2 (固定到兼容 go1.23 的版本)
- 本地实跑: 8 个端点对真实 OFF 数据返回正确(barcode/search/nutriments/msrp/brands/categories/source/404)

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -12,12 +12,31 @@ jobs:
     defaults:
       run:
         working-directory: api
+    services:
+      postgres:
+        image: postgres:16-alpine
+        env:
+          POSTGRES_USER: opengoods
+          POSTGRES_PASSWORD: opengoods
+          POSTGRES_DB: opengoods
+        ports:
+          - "5432:5432"
+        options: >-
+          --health-cmd "pg_isready -U opengoods"
+          --health-interval 5s --health-timeout 5s --health-retries 10
+    env:
+      OPENGOODS_DATABASE_URL: postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
           go-version: "1.23"
           cache-dependency-path: api/go.sum
+      - name: Apply migrations
+        working-directory: .
+        run: |
+          go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate@v4.18.1
+          migrate -path migrations -database "$OPENGOODS_DATABASE_URL" up
       - name: Verify gofmt
         run: test -z "$(gofmt -l .)"
       - run: go vet ./...
@@ -43,3 +62,32 @@ jobs:
         run: ruff format --check .
       - name: Pytest
         run: pytest -q
+
+  migrations:
+    name: Migrations (postgres)
+    runs-on: ubuntu-latest
+    services:
+      postgres:
+        image: postgres:16-alpine
+        env:
+          POSTGRES_USER: opengoods
+          POSTGRES_PASSWORD: opengoods
+          POSTGRES_DB: opengoods
+        ports:
+          - "5432:5432"
+        options: >-
+          --health-cmd "pg_isready -U opengoods"
+          --health-interval 5s --health-timeout 5s --health-retries 10
+    env:
+      DBURL: postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.23"
+      - name: Install golang-migrate
+        run: go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate@v4.18.1
+      - name: Migrate up
+        run: migrate -path migrations -database "$DBURL" up
+      - name: Migrate down (reversibility)
+        run: migrate -path migrations -database "$DBURL" down -all

api/cmd/server/main.go

@@ -2,20 +2,39 @@
 package main
 
 import (
+	"context"
 	"log"
 	"net/http"
 	"time"
 
+	"github.com/jackc/pgx/v5/pgxpool"
+
 	"github.com/baicai2026-baicai/goods/api/internal/config"
 	"github.com/baicai2026-baicai/goods/api/internal/handler"
+	"github.com/baicai2026-baicai/goods/api/internal/store"
 )
 
 func main() {
 	cfg := config.Load()
 
+	ctx := context.Background()
+	pool, err := pgxpool.New(ctx, cfg.DatabaseURL)
+	if err != nil {
+		log.Fatalf("failed to create db pool: %v", err)
+	}
+	defer pool.Close()
+
+	pingCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+	if err := pool.Ping(pingCtx); err != nil {
+		log.Printf("warning: database not reachable at startup: %v", err)
+	}
+
+	h := handler.New(store.New(pool))
+
 	srv := &http.Server{
 		Addr:              cfg.Addr,
-		Handler:           handler.Router(),
+		Handler:           h.Router(),
 		ReadHeaderTimeout: 10 * time.Second,
 	}
 

api/go.mod

@@ -2,4 +2,16 @@ module github.com/baicai2026-baicai/goods/api
 
 go 1.23.4
 
-require github.com/go-chi/chi/v5 v5.1.0
+require (
+	github.com/go-chi/chi/v5 v5.1.0
+	github.com/jackc/pgx/v5 v5.7.2
+)
+
+require (
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	golang.org/x/crypto v0.31.0 // indirect
+	golang.org/x/sync v0.10.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
+)

api/go.sum

@@ -1,2 +1,30 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-chi/chi/v5 v5.1.0 h1:acVI1TYaD+hhedDJ3r54HyA6sExp3HfXq7QWEEY/xMw=
 github.com/go-chi/chi/v5 v5.1.0/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.7.2 h1:mLoDLV6sonKlvjIEsV56SkWNCnuNv531l94GaIzO+XI=
+github.com/jackc/pgx/v5 v5.7.2/go.mod h1:ncY89UGWxg82EykZUwSpUKEfccBGGYq1xjrOpsbsfGQ=
+github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

api/internal/handler/handler.go

@@ -1,5 +1,4 @@
 // Package handler wires up the public, read-only OpenGoods HTTP API.
-//
 // The OpenGoods service is a public-good product information API: it only
 // collects and serves product facts. It exposes no purchase, checkout, or
 // commerce endpoints by design.
@@ -7,48 +6,188 @@ package handler
 
 import (
 	"encoding/json"
+	"errors"
 	"net/http"
+	"strconv"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
+
+	"github.com/baicai2026-baicai/goods/api/internal/store"
 )
 
 // APIVersion is the current public API version prefix.
 const APIVersion = "v1"
 
+const (
+	defaultPageSize = 20
+	maxPageSize     = 100
+)
+
+// Handler holds dependencies shared by the HTTP routes.
+type Handler struct {
+	store *store.Store
+}
+
+// New constructs a Handler backed by the given store.
+func New(s *store.Store) *Handler {
+	return &Handler{store: s}
+}
+
 // Router builds the top-level HTTP handler with middleware and routes mounted.
-func Router() http.Handler {
+func (h *Handler) Router() http.Handler {
 	r := chi.NewRouter()
 	r.Use(middleware.RequestID)
 	r.Use(middleware.RealIP)
 	r.Use(middleware.Recoverer)
 
-	r.Get("/healthz", Healthz)
+	r.Get("/healthz", h.Healthz)
 
 	r.Route("/api/"+APIVersion, func(r chi.Router) {
 		r.Route("/products", func(r chi.Router) {
-			r.Get("/barcode/{gtin}", notImplemented)
-			r.Get("/search", notImplemented)
-			r.Get("/{id}", notImplemented)
-			r.Get("/{id}/nutriments", notImplemented)
-			r.Get("/{id}/msrp", notImplemented)
+			r.Get("/barcode/{gtin}", h.ProductByBarcode)
+			r.Get("/search", h.SearchProducts)
+			r.Get("/{id}", h.ProductByID)
+			r.Get("/{id}/nutriments", h.ProductNutriments)
+			r.Get("/{id}/msrp", h.ProductMSRP)
 		})
-		r.Get("/brands", notImplemented)
-		r.Get("/categories", notImplemented)
-		r.Get("/sources/{id}", notImplemented)
+		r.Get("/brands", h.ListBrands)
+		r.Get("/categories", h.ListCategories)
+		r.Get("/sources/{id}", h.SourceByID)
 	})
 
 	return r
 }
 
 // Healthz reports liveness of the service.
-func Healthz(w http.ResponseWriter, r *http.Request) {
+func (h *Handler) Healthz(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
 }
 
-// notImplemented is a placeholder for endpoints scoped to later milestones.
-func notImplemented(w http.ResponseWriter, r *http.Request) {
-	writeError(w, r, http.StatusNotImplemented, "not_implemented", "endpoint not implemented yet")
+// ProductByBarcode returns a product by its GTIN.
+func (h *Handler) ProductByBarcode(w http.ResponseWriter, r *http.Request) {
+	p, err := h.store.ProductByGTIN(r.Context(), chi.URLParam(r, "gtin"))
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, p)
+}
+
+// ProductByID returns a product by its UUID.
+func (h *Handler) ProductByID(w http.ResponseWriter, r *http.Request) {
+	p, err := h.store.ProductByID(r.Context(), chi.URLParam(r, "id"))
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, p)
+}
+
+// SearchProducts runs a fuzzy name search with optional category filter + paging.
+func (h *Handler) SearchProducts(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query().Get("q")
+	category := r.URL.Query().Get("category")
+	page, size := pageParams(r)
+
+	items, total, err := h.store.SearchProducts(r.Context(), q, category, size, (page-1)*size)
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"items": items,
+		"page":  page,
+		"size":  size,
+		"total": total,
+	})
+}
+
+// ProductNutriments returns just the nutrition facts of a product.
+func (h *Handler) ProductNutriments(w http.ResponseWriter, r *http.Request) {
+	n, err := h.store.Nutriments(r.Context(), chi.URLParam(r, "id"))
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, n)
+}
+
+// ProductMSRP returns official suggested retail price snapshots (no purchase link).
+func (h *Handler) ProductMSRP(w http.ResponseWriter, r *http.Request) {
+	items, err := h.store.ListMSRP(r.Context(), chi.URLParam(r, "id"))
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"items":      items,
+		"disclaimer": "厂商建议零售价历史快照，仅供参考，不构成购买建议，本服务不提供任何购买入口。",
+	})
+}
+
+// ListBrands returns a paginated list of brands.
+func (h *Handler) ListBrands(w http.ResponseWriter, r *http.Request) {
+	page, size := pageParams(r)
+	items, total, err := h.store.ListBrands(r.Context(), size, (page-1)*size)
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"items": items, "page": page, "size": size, "total": total,
+	})
+}
+
+// ListCategories returns the full category tree.
+func (h *Handler) ListCategories(w http.ResponseWriter, r *http.Request) {
+	items, err := h.store.ListCategories(r.Context())
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"items": items})
+}
+
+// SourceByID returns a single data source.
+func (h *Handler) SourceByID(w http.ResponseWriter, r *http.Request) {
+	src, err := h.store.SourceByID(r.Context(), chi.URLParam(r, "id"))
+	if h.handleErr(w, r, err) {
+		return
+	}
+	writeJSON(w, http.StatusOK, src)
+}
+
+// handleErr writes an appropriate error response; returns true if it handled one.
+func (h *Handler) handleErr(w http.ResponseWriter, r *http.Request, err error) bool {
+	if err == nil {
+		return false
+	}
+	if errors.Is(err, store.ErrNotFound) {
+		writeError(w, r, http.StatusNotFound, "not_found", "resource not found")
+		return true
+	}
+	writeError(w, r, http.StatusInternalServerError, "internal_error", "internal server error")
+	return true
+}
+
+func pageParams(r *http.Request) (page, size int) {
+	page = atoiDefault(r.URL.Query().Get("page"), 1)
+	if page < 1 {
+		page = 1
+	}
+	size = atoiDefault(r.URL.Query().Get("size"), defaultPageSize)
+	if size < 1 {
+		size = defaultPageSize
+	}
+	if size > maxPageSize {
+		size = maxPageSize
+	}
+	return page, size
+}
+
+func atoiDefault(s string, fallback int) int {
+	if s == "" {
+		return fallback
+	}
+	v, err := strconv.Atoi(s)
+	if err != nil {
+		return fallback
+	}
+	return v
 }
 
 func writeJSON(w http.ResponseWriter, status int, body any) {

api/internal/handler/handler_db_test.go

@@ -0,0 +1,134 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/baicai2026-baicai/goods/api/internal/store"
+)
+
+// newTestHandler connects to the test database, skipping if unavailable or
+// unmigrated. It inserts a known product (cleaned up via t.Cleanup) so the
+// endpoint assertions are deterministic.
+func newTestHandler(t *testing.T) (*Handler, string) {
+	t.Helper()
+	dsn := os.Getenv("OPENGOODS_DATABASE_URL")
+	if dsn == "" {
+		dsn = "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		t.Skipf("no database: %v", err)
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		t.Skipf("database not reachable: %v", err)
+	}
+
+	var hasProduct bool
+	if err := pool.QueryRow(ctx, "SELECT to_regclass('public.product') IS NOT NULL").Scan(&hasProduct); err != nil || !hasProduct {
+		pool.Close()
+		t.Skip("migrations not applied")
+	}
+
+	gtin := "4006381333931"
+	_, err = pool.Exec(context.Background(), `
+		INSERT INTO product (gtin, name, category_id, net_content_value, net_content_unit)
+		VALUES ($1, 'Test Cola', (SELECT id FROM category WHERE path='food.beverages.carbonated'), 330, 'ml')
+		ON CONFLICT (gtin) WHERE gtin IS NOT NULL DO UPDATE SET name = EXCLUDED.name`, gtin)
+	if err != nil {
+		pool.Close()
+		t.Fatalf("seed insert failed: %v", err)
+	}
+	var pid string
+	_ = pool.QueryRow(context.Background(), "SELECT id FROM product WHERE gtin=$1", gtin).Scan(&pid)
+	_, _ = pool.Exec(context.Background(), `
+		INSERT INTO food_detail (product_id, nutrition_basis, nutriments)
+		VALUES ($1, 'per_100ml', '{"energy_kcal": 42}'::jsonb)
+		ON CONFLICT (product_id) DO UPDATE SET nutriments = EXCLUDED.nutriments`, pid)
+
+	t.Cleanup(func() {
+		_, _ = pool.Exec(context.Background(), "DELETE FROM product WHERE gtin=$1", gtin)
+		pool.Close()
+	})
+	return New(store.New(pool)), gtin
+}
+
+func doGET(t *testing.T, h *Handler, path string) *httptest.ResponseRecorder {
+	t.Helper()
+	req := httptest.NewRequest(http.MethodGet, path, nil)
+	rec := httptest.NewRecorder()
+	h.Router().ServeHTTP(rec, req)
+	return rec
+}
+
+func TestProductByBarcode(t *testing.T) {
+	h, gtin := newTestHandler(t)
+	rec := doGET(t, h, "/api/"+APIVersion+"/products/barcode/"+gtin)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, body = %s", rec.Code, rec.Body.String())
+	}
+	var p store.Product
+	if err := json.NewDecoder(rec.Body).Decode(&p); err != nil {
+		t.Fatal(err)
+	}
+	if p.Name != "Test Cola" || p.GTIN == nil || *p.GTIN != gtin {
+		t.Fatalf("unexpected product: %+v", p)
+	}
+	if p.CategoryPath == nil || *p.CategoryPath != "food.beverages.carbonated" {
+		t.Fatalf("category not joined: %+v", p.CategoryPath)
+	}
+}
+
+func TestProductByBarcodeNotFound(t *testing.T) {
+	h, _ := newTestHandler(t)
+	rec := doGET(t, h, "/api/"+APIVersion+"/products/barcode/0000000000000")
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("expected 404, got %d", rec.Code)
+	}
+}
+
+func TestSearchProducts(t *testing.T) {
+	h, _ := newTestHandler(t)
+	rec := doGET(t, h, "/api/"+APIVersion+"/products/search?q=Cola&category=food.beverages")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d", rec.Code)
+	}
+	var body struct {
+		Items []store.ProductSummary `json:"items"`
+		Total int                    `json:"total"`
+	}
+	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
+		t.Fatal(err)
+	}
+	if body.Total < 1 {
+		t.Fatalf("expected at least 1 result, got %d", body.Total)
+	}
+}
+
+func TestListCategories(t *testing.T) {
+	h, _ := newTestHandler(t)
+	rec := doGET(t, h, "/api/"+APIVersion+"/categories")
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d", rec.Code)
+	}
+	var body struct {
+		Items []store.Category `json:"items"`
+	}
+	if err := json.NewDecoder(rec.Body).Decode(&body); err != nil {
+		t.Fatal(err)
+	}
+	if len(body.Items) < 20 {
+		t.Fatalf("expected seeded categories, got %d", len(body.Items))
+	}
+}

api/internal/handler/handler_test.go

@@ -11,7 +11,7 @@ func TestHealthz(t *testing.T) {
 	req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
 	rec := httptest.NewRecorder()
 
-	Router().ServeHTTP(rec, req)
+	New(nil).Router().ServeHTTP(rec, req)
 
 	if rec.Code != http.StatusOK {
 		t.Fatalf("expected status %d, got %d", http.StatusOK, rec.Code)
@@ -26,13 +26,23 @@ func TestHealthz(t *testing.T) {
 	}
 }
 
-func TestProductEndpointNotImplemented(t *testing.T) {
-	req := httptest.NewRequest(http.MethodGet, "/api/"+APIVersion+"/products/barcode/3017624010701", nil)
-	rec := httptest.NewRecorder()
-
-	Router().ServeHTTP(rec, req)
-
-	if rec.Code != http.StatusNotImplemented {
-		t.Fatalf("expected status %d, got %d", http.StatusNotImplemented, rec.Code)
+func TestPageParams(t *testing.T) {
+	cases := []struct {
+		query            string
+		wantPage, wantSz int
+	}{
+		{"", 1, defaultPageSize},
+		{"page=3&size=10", 3, 10},
+		{"page=0&size=-5", 1, defaultPageSize},
+		{"size=1000", 1, maxPageSize},
+		{"page=abc", 1, defaultPageSize},
+	}
+	for _, c := range cases {
+		req := httptest.NewRequest(http.MethodGet, "/?"+c.query, nil)
+		page, size := pageParams(req)
+		if page != c.wantPage || size != c.wantSz {
+			t.Errorf("query %q: got page=%d size=%d, want page=%d size=%d",
+				c.query, page, size, c.wantPage, c.wantSz)
+		}
 	}
 }

api/internal/store/store.go

@@ -0,0 +1,278 @@
+// Package store is the read-only data access layer for the OpenGoods API.
+// It only issues SELECT queries; all writes happen in the Python ingestion path.
+package store
+
+import (
+	"context"
+	"errors"
+	"strconv"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// ErrNotFound is returned when a requested row does not exist.
+var ErrNotFound = errors.New("not found")
+
+// Store wraps a PostgreSQL connection pool.
+type Store struct {
+	pool *pgxpool.Pool
+}
+
+// New constructs a Store from an existing pgx pool.
+func New(pool *pgxpool.Pool) *Store {
+	return &Store{pool: pool}
+}
+
+// Ping verifies database connectivity.
+func (s *Store) Ping(ctx context.Context) error {
+	return s.pool.Ping(ctx)
+}
+
+// Product is the full public view of a product.
+type Product struct {
+	ID              string         `json:"id"`
+	GTIN            *string        `json:"gtin"`
+	Name            string         `json:"name"`
+	Brand           *string        `json:"brand"`
+	CategoryPath    *string        `json:"category_path"`
+	GPCBrickCode    *string        `json:"gpc_brick_code"`
+	NetContentValue *float64       `json:"net_content_value"`
+	NetContentUnit  *string        `json:"net_content_unit"`
+	CountryOfOrigin *string        `json:"country_of_origin"`
+	QualityScore    float64        `json:"quality_score"`
+	Nutriments      map[string]any `json:"nutriments,omitempty"`
+	NutritionBasis  *string        `json:"nutrition_basis,omitempty"`
+	NutriScore      *string        `json:"nutri_score,omitempty"`
+	Ingredients     *string        `json:"ingredients_text,omitempty"`
+	Allergens       []string       `json:"allergens,omitempty"`
+	Additives       []string       `json:"additives,omitempty"`
+}
+
+// ProductSummary is a lightweight row used in search/listing responses.
+type ProductSummary struct {
+	ID           string  `json:"id"`
+	GTIN         *string `json:"gtin"`
+	Name         string  `json:"name"`
+	Brand        *string `json:"brand"`
+	CategoryPath *string `json:"category_path"`
+}
+
+const productSelect = `
+SELECT p.id, p.gtin, p.name, b.name, c.path::text, p.gpc_brick_code,
+       p.net_content_value, p.net_content_unit, p.country_of_origin, p.quality_score,
+       f.nutriments, f.nutrition_basis, f.nutri_score, f.ingredients_text,
+       f.allergens, f.additives
+FROM product p
+LEFT JOIN brand b ON b.id = p.brand_id
+LEFT JOIN category c ON c.id = p.category_id
+LEFT JOIN food_detail f ON f.product_id = p.id
+`
+
+func scanProduct(row pgx.Row) (*Product, error) {
+	var p Product
+	err := row.Scan(
+		&p.ID, &p.GTIN, &p.Name, &p.Brand, &p.CategoryPath, &p.GPCBrickCode,
+		&p.NetContentValue, &p.NetContentUnit, &p.CountryOfOrigin, &p.QualityScore,
+		&p.Nutriments, &p.NutritionBasis, &p.NutriScore, &p.Ingredients,
+		&p.Allergens, &p.Additives,
+	)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &p, nil
+}
+
+// ProductByGTIN looks up an active product by its barcode.
+func (s *Store) ProductByGTIN(ctx context.Context, gtin string) (*Product, error) {
+	row := s.pool.QueryRow(ctx, productSelect+" WHERE p.gtin = $1 AND p.status = 'active'", gtin)
+	return scanProduct(row)
+}
+
+// ProductByID looks up a product by its UUID.
+func (s *Store) ProductByID(ctx context.Context, id string) (*Product, error) {
+	row := s.pool.QueryRow(ctx, productSelect+" WHERE p.id = $1", id)
+	return scanProduct(row)
+}
+
+// SearchProducts performs a fuzzy name search with optional category subtree filter.
+func (s *Store) SearchProducts(ctx context.Context, q, category string, limit, offset int) ([]ProductSummary, int, error) {
+	args := []any{}
+	where := "WHERE p.status = 'active'"
+	if q != "" {
+		args = append(args, q)
+		where += " AND p.name ILIKE '%' || $1 || '%'"
+	}
+	if category != "" {
+		args = append(args, category)
+		where += " AND c.path <@ $" + strconv.Itoa(len(args)) + "::ltree"
+	}
+
+	countSQL := "SELECT count(*) FROM product p LEFT JOIN category c ON c.id = p.category_id " + where
+	var total int
+	if err := s.pool.QueryRow(ctx, countSQL, args...).Scan(&total); err != nil {
+		return nil, 0, err
+	}
+
+	args = append(args, limit, offset)
+	listSQL := `
+SELECT p.id, p.gtin, p.name, b.name, c.path::text
+FROM product p
+LEFT JOIN brand b ON b.id = p.brand_id
+LEFT JOIN category c ON c.id = p.category_id ` + where +
+		" ORDER BY p.name LIMIT $" + strconv.Itoa(len(args)-1) + " OFFSET $" + strconv.Itoa(len(args))
+
+	rows, err := s.pool.Query(ctx, listSQL, args...)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer rows.Close()
+
+	out := []ProductSummary{}
+	for rows.Next() {
+		var ps ProductSummary
+		if err := rows.Scan(&ps.ID, &ps.GTIN, &ps.Name, &ps.Brand, &ps.CategoryPath); err != nil {
+			return nil, 0, err
+		}
+		out = append(out, ps)
+	}
+	return out, total, rows.Err()
+}
+
+// Nutriments returns just the nutrition payload for a product.
+type Nutriments struct {
+	ProductID  string         `json:"product_id"`
+	Basis      *string        `json:"basis"`
+	NutriScore *string        `json:"nutri_score"`
+	Values     map[string]any `json:"values"`
+}
+
+// Nutriments fetches the nutrition facts of a product.
+func (s *Store) Nutriments(ctx context.Context, id string) (*Nutriments, error) {
+	var n Nutriments
+	n.ProductID = id
+	err := s.pool.QueryRow(ctx,
+		"SELECT nutriments, nutrition_basis, nutri_score FROM food_detail WHERE product_id = $1", id,
+	).Scan(&n.Values, &n.Basis, &n.NutriScore)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &n, nil
+}
+
+// MSRP is an official suggested retail price snapshot (never a purchase link).
+type MSRP struct {
+	Amount        float64 `json:"amount"`
+	Currency      string  `json:"currency"`
+	Region        string  `json:"region"`
+	EffectiveDate *string `json:"effective_date"`
+	SourceURL     *string `json:"source_url"`
+	Note          *string `json:"note"`
+}
+
+// ListMSRP returns all MSRP snapshots for a product.
+func (s *Store) ListMSRP(ctx context.Context, id string) ([]MSRP, error) {
+	rows, err := s.pool.Query(ctx,
+		`SELECT amount, currency, region, effective_date::text, source_url, note
+		 FROM product_msrp WHERE product_id = $1 ORDER BY effective_date DESC NULLS LAST`, id)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []MSRP{}
+	for rows.Next() {
+		var m MSRP
+		if err := rows.Scan(&m.Amount, &m.Currency, &m.Region, &m.EffectiveDate, &m.SourceURL, &m.Note); err != nil {
+			return nil, err
+		}
+		out = append(out, m)
+	}
+	return out, rows.Err()
+}
+
+// Brand is a public brand entry.
+type Brand struct {
+	ID   string `json:"id"`
+	Name string `json:"name"`
+}
+
+// ListBrands returns brands ordered by name.
+func (s *Store) ListBrands(ctx context.Context, limit, offset int) ([]Brand, int, error) {
+	var total int
+	if err := s.pool.QueryRow(ctx, "SELECT count(*) FROM brand").Scan(&total); err != nil {
+		return nil, 0, err
+	}
+	rows, err := s.pool.Query(ctx, "SELECT id, name FROM brand ORDER BY name LIMIT $1 OFFSET $2", limit, offset)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer rows.Close()
+	out := []Brand{}
+	for rows.Next() {
+		var b Brand
+		if err := rows.Scan(&b.ID, &b.Name); err != nil {
+			return nil, 0, err
+		}
+		out = append(out, b)
+	}
+	return out, total, rows.Err()
+}
+
+// Category is a node in the self-built category tree.
+type Category struct {
+	ID           string  `json:"id"`
+	NameZH       string  `json:"name_zh"`
+	NameEN       *string `json:"name_en"`
+	Path         string  `json:"path"`
+	GPCBrickCode *string `json:"gpc_brick_code"`
+	Level        int     `json:"level"`
+}
+
+// ListCategories returns the full category tree ordered by path.
+func (s *Store) ListCategories(ctx context.Context) ([]Category, error) {
+	rows, err := s.pool.Query(ctx,
+		"SELECT id, name_zh, name_en, path::text, gpc_brick_code, level FROM category ORDER BY path")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []Category{}
+	for rows.Next() {
+		var c Category
+		if err := rows.Scan(&c.ID, &c.NameZH, &c.NameEN, &c.Path, &c.GPCBrickCode, &c.Level); err != nil {
+			return nil, err
+		}
+		out = append(out, c)
+	}
+	return out, rows.Err()
+}
+
+// Source describes a data source with its license and trust weight.
+type Source struct {
+	ID          string  `json:"id"`
+	Name        string  `json:"name"`
+	Homepage    *string `json:"homepage"`
+	License     *string `json:"license"`
+	TrustWeight float64 `json:"trust_weight"`
+}
+
+// SourceByID fetches a single data source.
+func (s *Store) SourceByID(ctx context.Context, id string) (*Source, error) {
+	var src Source
+	err := s.pool.QueryRow(ctx,
+		"SELECT id, name, homepage, license, trust_weight FROM source WHERE id = $1", id,
+	).Scan(&src.ID, &src.Name, &src.Homepage, &src.License, &src.TrustWeight)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &src, nil
+}

docs/etl-openfoodfacts.md

@@ -0,0 +1,38 @@
+# ETL: Open Food Facts 导入 (M2)
+
+把 Open Food Facts (OFF, ODbL 许可) 的食品数据采集、转换并入库。只有 Python 采集侧写库，每条记录都以 `openfoodfacts` 为来源记录**字段级溯源**。
+
+## 流程
+```
+OFF API / dump(jsonl[.gz])
+  → adapters/openfoodfacts.py   # 读取(限速 + User-Agent) / 解析 dump
+  → etl/transform.py            # 字段映射 + 单位归一 + 营养 per_100g + 分类映射(关键词)
+  → etl/load.py                 # psycopg upsert(product/food_detail/product_image) + product_source 溯源
+```
+
+## 运行
+先确保本地依赖与迁移就绪：`docker compose up -d postgres` + `migrate ... up`。
+
+```bash
+# 用 OFF API 拉指定条码(客户端限速, 默认 4s/次)
+python -m opengoods.jobs.seed_off --barcodes 3017624010701 5449000000996
+
+# 用下载好的 OFF dump 批量导入(可 .gz), 限制条数
+python -m opengoods.jobs.seed_off --dump products.jsonl.gz --limit 1000
+```
+DSN 默认读 `OPENGOODS_DATABASE_URL`。
+
+## 字段映射要点
+| OFF | OpenGoods | 处理 |
+|-----|-----------|------|
+| `code` | `product.gtin` | GTIN-8/12/13/14 校验位验证, 不合法则不作为 gtin |
+| `product_name_zh/_/_en` | `product.name` | 优先中文 |
+| `brands` | `brand` | 取第一个, normalized_name 去重 |
+| `quantity` | `net_content_*` | 解析 "500 g"/"1,5 L" → 经 `units.py` 归一(原始+归一双存) |
+| `nutriments.*_100g` | `food_detail.nutriments` | per_100g; 能量 kJ/kcal 双存, 缺一自动换算 |
+| `allergens_tags`/`additives_tags` | `allergens`/`additives` | 去 `en:` 前缀 |
+| `nutriscore_grade` | `nutri_score` | 大写单字母 |
+| `categories*`/name | `category_id` | 关键词映射到自建品类树(起步版, 后续换 OFF 分类→GPC 映射表) |
+| `image_front_url` | `product_image` | 标 CC-BY-SA 许可 |
+
+> 全量 dump 约数 GB；CI 与单测用 fixture 离线验证 transform，DB 集成测试在无库时自动跳过。

ingestion/opengoods/adapters/openfoodfacts.py

@@ -0,0 +1,86 @@
+"""Open Food Facts (OFF) source adapter.
+
+Fetches raw product records either from the OFF read API (one product per
+barcode) or from a downloaded JSONL dump file. OFF data is licensed under the
+Open Database License (ODbL); product images are CC-BY-SA. We record OFF as the
+source for every field we ingest.
+
+The adapter is read-only and rate-limited to stay well within OFF's API limits
+(<= ~15 req/min/IP for product reads) and to be a good citizen.
+"""
+
+from __future__ import annotations
+
+import json
+import time
+from collections.abc import Iterator
+from pathlib import Path
+
+import httpx
+
+SOURCE_NAME = "openfoodfacts"
+OFF_LICENSE = "ODbL"
+USER_AGENT = "OpenGoods/0.1 (+https://github.com/baicai2026-baicai/goods) public-good product API"
+
+# Conservative client-side spacing between API calls (seconds).
+_DEFAULT_MIN_INTERVAL = 4.0
+_API_URL = "https://world.openfoodfacts.org/api/v2/product/{barcode}.json"
+
+
+class OpenFoodFactsAdapter:
+    """Read product records from the OFF API."""
+
+    source_name = SOURCE_NAME
+
+    def __init__(
+        self,
+        client: httpx.Client | None = None,
+        min_interval: float = _DEFAULT_MIN_INTERVAL,
+    ) -> None:
+        self._client = client or httpx.Client(headers={"User-Agent": USER_AGENT}, timeout=30.0)
+        self._min_interval = min_interval
+        self._last_call = 0.0
+
+    def _throttle(self) -> None:
+        elapsed = time.monotonic() - self._last_call
+        wait = self._min_interval - elapsed
+        if wait > 0:
+            time.sleep(wait)
+        self._last_call = time.monotonic()
+
+    def fetch_barcode(self, barcode: str) -> dict | None:
+        """Fetch a single product by barcode; return the raw `product` dict."""
+        self._throttle()
+        resp = self._client.get(_API_URL.format(barcode=barcode))
+        resp.raise_for_status()
+        payload = resp.json()
+        if payload.get("status") != 1:
+            return None
+        return payload["product"]
+
+    def fetch(self, barcodes: list[str]) -> Iterator[dict]:
+        """Yield raw product records for the given barcodes."""
+        for code in barcodes:
+            record = self.fetch_barcode(code)
+            if record is not None:
+                yield record
+
+
+def read_dump(path: str | Path) -> Iterator[dict]:
+    """Yield raw product records from an OFF JSONL dump file.
+
+    Each line is one product JSON object (the format of OFF's .jsonl export).
+    Supports plain or .gz files.
+    """
+    p = Path(path)
+    if p.suffix == ".gz":
+        import gzip
+
+        opener = lambda: gzip.open(p, "rt", encoding="utf-8")  # noqa: E731
+    else:
+        opener = lambda: open(p, encoding="utf-8")  # noqa: E731
+    with opener() as fh:
+        for line in fh:
+            line = line.strip()
+            if line:
+                yield json.loads(line)

ingestion/opengoods/etl/load.py

@@ -0,0 +1,198 @@
+"""Load transformed product records into the OpenGoods PostgreSQL database.
+
+Only the ingestion side writes to the database. Every load records OFF as the
+source with field-level provenance in `product_source`.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+from typing import Any
+
+import psycopg
+from psycopg.types.json import Jsonb
+
+from opengoods.adapters.openfoodfacts import OFF_LICENSE, SOURCE_NAME
+
+OFF_HOMEPAGE = "https://world.openfoodfacts.org"
+
+
+def default_dsn() -> str:
+    return os.environ.get(
+        "OPENGOODS_DATABASE_URL",
+        "postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable",
+    )
+
+
+def _normalize_brand(name: str) -> str:
+    return " ".join(name.lower().split())
+
+
+def ensure_source(conn: psycopg.Connection) -> str:
+    """Upsert the Open Food Facts source row and return its id."""
+    row = conn.execute(
+        """
+        INSERT INTO source (name, homepage, license, trust_weight)
+        VALUES (%s, %s, %s, %s)
+        ON CONFLICT (name) DO UPDATE SET homepage = EXCLUDED.homepage
+        RETURNING id
+        """,
+        (SOURCE_NAME, OFF_HOMEPAGE, OFF_LICENSE, 0.7),
+    ).fetchone()
+    return row[0]
+
+
+def _ensure_brand(conn: psycopg.Connection, name: str | None) -> str | None:
+    if not name:
+        return None
+    row = conn.execute(
+        """
+        INSERT INTO brand (name, normalized_name)
+        VALUES (%s, %s)
+        ON CONFLICT (normalized_name) DO UPDATE SET name = brand.name
+        RETURNING id
+        """,
+        (name, _normalize_brand(name)),
+    ).fetchone()
+    return row[0]
+
+
+def _category_id(conn: psycopg.Connection, path: str | None) -> tuple[str | None, str | None]:
+    if not path:
+        return None, None
+    row = conn.execute(
+        "SELECT id, gpc_brick_code FROM category WHERE path = %s::ltree", (path,)
+    ).fetchone()
+    return (row[0], row[1]) if row else (None, None)
+
+
+def load_record(conn: psycopg.Connection, rec: dict[str, Any], source_id: str, raw: dict) -> str:
+    """Upsert one transformed record; return the product id."""
+    brand_id = _ensure_brand(conn, rec.get("brand"))
+    category_id, gpc_brick = _category_id(conn, rec.get("category_path"))
+
+    fields = ["name", "brand", "net_content", "category", "country_of_origin"]
+
+    if rec.get("gtin"):
+        prod = conn.execute(
+            """
+            INSERT INTO product (gtin, name, brand_id, category_id, gpc_brick_code,
+                net_content_value, net_content_unit, net_content_canonical,
+                country_of_origin, attributes)
+            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)
+            ON CONFLICT (gtin) WHERE gtin IS NOT NULL DO UPDATE SET
+                name = EXCLUDED.name,
+                brand_id = COALESCE(EXCLUDED.brand_id, product.brand_id),
+                category_id = COALESCE(EXCLUDED.category_id, product.category_id),
+                gpc_brick_code = COALESCE(EXCLUDED.gpc_brick_code, product.gpc_brick_code),
+                net_content_value = EXCLUDED.net_content_value,
+                net_content_unit = EXCLUDED.net_content_unit,
+                net_content_canonical = EXCLUDED.net_content_canonical,
+                country_of_origin = EXCLUDED.country_of_origin
+            RETURNING id
+            """,
+            (
+                rec["gtin"],
+                rec["name"],
+                brand_id,
+                category_id,
+                gpc_brick,
+                rec.get("net_content_value"),
+                rec.get("net_content_unit"),
+                rec.get("net_content_canonical"),
+                rec.get("country_of_origin"),
+                Jsonb({}),
+            ),
+        ).fetchone()
+    else:
+        prod = conn.execute(
+            """
+            INSERT INTO product (name, brand_id, category_id, gpc_brick_code,
+                net_content_value, net_content_unit, net_content_canonical,
+                country_of_origin, attributes)
+            VALUES (%s,%s,%s,%s,%s,%s,%s,%s,%s)
+            RETURNING id
+            """,
+            (
+                rec["name"],
+                brand_id,
+                category_id,
+                gpc_brick,
+                rec.get("net_content_value"),
+                rec.get("net_content_unit"),
+                rec.get("net_content_canonical"),
+                rec.get("country_of_origin"),
+                Jsonb({}),
+            ),
+        ).fetchone()
+    product_id = prod[0]
+
+    food = rec.get("food") or {}
+    conn.execute(
+        """
+        INSERT INTO food_detail (product_id, ingredients_text, allergens, additives,
+            nutriments, nutrition_basis, serving_size, nutri_score)
+        VALUES (%s,%s,%s,%s,%s,%s,%s,%s)
+        ON CONFLICT (product_id) DO UPDATE SET
+            ingredients_text = EXCLUDED.ingredients_text,
+            allergens = EXCLUDED.allergens,
+            additives = EXCLUDED.additives,
+            nutriments = EXCLUDED.nutriments,
+            nutrition_basis = EXCLUDED.nutrition_basis,
+            serving_size = EXCLUDED.serving_size,
+            nutri_score = EXCLUDED.nutri_score
+        """,
+        (
+            product_id,
+            food.get("ingredients_text"),
+            food.get("allergens") or [],
+            food.get("additives") or [],
+            Jsonb(food.get("nutriments") or {}),
+            food.get("nutrition_basis"),
+            food.get("serving_size"),
+            food.get("nutri_score"),
+        ),
+    )
+
+    if rec.get("image_url"):
+        conn.execute(
+            """
+            INSERT INTO product_image (product_id, url, kind, license, source_id)
+            VALUES (%s,%s,'front',%s,%s)
+            """,
+            (product_id, rec["image_url"], "CC-BY-SA", source_id),
+        )
+        fields.append("image")
+
+    conn.execute(
+        """
+        INSERT INTO product_source (product_id, source_id, url, fields, fetched_at, raw)
+        VALUES (%s,%s,%s,%s, now(), %s)
+        """,
+        (
+            product_id,
+            source_id,
+            f"{OFF_HOMEPAGE}/product/{rec.get('gtin') or ''}",
+            fields,
+            Jsonb(_jsonable(raw)),
+        ),
+    )
+    return product_id
+
+
+def _jsonable(raw: dict) -> dict:
+    """Drop values that are not JSON-serializable from a raw record."""
+    try:
+        json.dumps(raw)
+        return raw
+    except (TypeError, ValueError):
+        return {k: v for k, v in raw.items() if _is_jsonable(v)}
+
+
+def _is_jsonable(v: object) -> bool:
+    try:
+        json.dumps(v)
+        return True
+    except (TypeError, ValueError):
+        return False

ingestion/opengoods/etl/transform.py

@@ -0,0 +1,159 @@
+"""Transform raw Open Food Facts records into the OpenGoods internal shape.
+
+Pure functions (no DB, no network) so they are easy to unit-test against
+fixtures. The output dict mirrors the columns the loader writes.
+"""
+
+from __future__ import annotations
+
+import re
+from decimal import Decimal
+
+from opengoods.units import UnitError, normalize
+
+# OFF nutriment key -> our attribute key. Energy handled separately.
+_NUTRIMENT_KEYS = {
+    "proteins_100g": "proteins",
+    "fat_100g": "fat",
+    "saturated-fat_100g": "saturated_fat",
+    "carbohydrates_100g": "carbohydrates",
+    "sugars_100g": "sugars",
+    "salt_100g": "salt",
+}
+
+# Very small keyword -> category path map (starter; replaced by a proper
+# OFF taxonomy -> GPC mapping table later).
+_CATEGORY_KEYWORDS: list[tuple[tuple[str, ...], str]] = [
+    (("water", "eau", "饮用水", "矿泉水"), "food.beverages.water"),
+    (("soda", "carbonated", "汽水", "碳酸"), "food.beverages.carbonated"),
+    (("juice", "jus", "果汁"), "food.beverages.juice"),
+    (("milk", "lait", "牛奶"), "food.dairy.milk"),
+    (("yogurt", "yoghurt", "yaourt", "酸奶"), "food.dairy.yogurt"),
+    (("cheese", "fromage", "奶酪", "干酪"), "food.dairy.cheese"),
+    (("bread", "pain", "面包"), "food.bakery.bread"),
+    (("biscuit", "cookie", "饼干"), "food.bakery.biscuits"),
+    (("chips", "crisps", "薯片", "膨化"), "food.snacks.chips"),
+    (("chocolate", "chocolat", "巧克力"), "food.snacks.chocolate"),
+    (("rice", "riz", "大米", "稻米"), "food.staple.rice"),
+    (("noodle", "pasta", "面条", "挂面"), "food.staple.noodles"),
+    (("oil", "huile", "食用油", "食油"), "food.staple.cooking_oil"),
+    (("soy sauce", "酱油"), "food.condiments.soy_sauce"),
+    (("salt", "sel", "食盐"), "food.condiments.salt"),
+]
+
+_QTY_RE = re.compile(r"(?P<value>\d+(?:[.,]\d+)?)\s*(?P<unit>[a-zA-Z\u4e00-\u9fff%]+)")
+
+
+def is_valid_gtin(code: str) -> bool:
+    """Validate a GTIN-8/12/13/14 using the standard check digit."""
+    if not code.isdigit() or len(code) not in (8, 12, 13, 14):
+        return False
+    digits = [int(c) for c in code]
+    check = digits[-1]
+    body = digits[:-1][::-1]
+    total = sum(d * (3 if i % 2 == 0 else 1) for i, d in enumerate(body))
+    return (10 - total % 10) % 10 == check
+
+
+def parse_quantity(text: str) -> tuple[Decimal, str] | None:
+    """Parse a free-text quantity like '500 g' or '1,5 L' -> (value, unit)."""
+    if not text:
+        return None
+    m = _QTY_RE.search(text)
+    if not m:
+        return None
+    value = Decimal(m.group("value").replace(",", "."))
+    return value, m.group("unit")
+
+
+def map_category(raw: dict) -> str | None:
+    """Best-effort map OFF categories/name to a self-built category path."""
+    haystack = " ".join(
+        str(raw.get(k, ""))
+        for k in ("categories", "categories_tags", "product_name", "product_name_en")
+    ).lower()
+    for keywords, path in _CATEGORY_KEYWORDS:
+        if any(kw.lower() in haystack for kw in keywords):
+            return path
+    return None
+
+
+def _clean_tags(tags: list[str] | None, prefix: str = "") -> list[str]:
+    out: list[str] = []
+    for t in tags or []:
+        v = t.split(":", 1)[-1] if ":" in t else t
+        v = v.strip().replace("-", " ")
+        if v:
+            out.append(v)
+    return out
+
+
+def transform_nutriments(off_nutriments: dict) -> dict:
+    """Build a nutriments dict on a per_100g basis with dual energy units."""
+    out: dict[str, object] = {}
+    for off_key, our_key in _NUTRIMENT_KEYS.items():
+        if off_key in off_nutriments and off_nutriments[off_key] is not None:
+            out[our_key] = float(off_nutriments[off_key])
+
+    kj = off_nutriments.get("energy-kj_100g")
+    kcal = off_nutriments.get("energy-kcal_100g")
+    if kj is None and kcal is not None:
+        kj = float(Decimal(str(kcal)) * Decimal("4.184"))
+    if kcal is None and kj is not None:
+        kcal = float(Decimal(str(kj)) / Decimal("4.184"))
+    if kj is not None:
+        out["energy_kj"] = round(float(kj), 3)
+    if kcal is not None:
+        out["energy_kcal"] = round(float(kcal), 3)
+    return out
+
+
+def transform(raw: dict) -> dict | None:
+    """Transform one raw OFF product record into an internal product dict.
+
+    Returns None if the record lacks a usable name.
+    """
+    name = raw.get("product_name_zh") or raw.get("product_name") or raw.get("product_name_en")
+    if not name:
+        return None
+
+    code = str(raw.get("code", "")).strip()
+    gtin = code if code and is_valid_gtin(code) else None
+
+    brands = raw.get("brands") or ""
+    brand = brands.split(",")[0].strip() or None
+
+    net_value = net_unit = net_canonical = None
+    parsed = parse_quantity(raw.get("quantity", ""))
+    if parsed:
+        value, unit = parsed
+        try:
+            norm = normalize(value, unit)
+            net_value, net_unit, net_canonical = (
+                norm.value,
+                norm.unit,
+                norm.canonical_value,
+            )
+        except UnitError:
+            net_value, net_unit = value, unit
+
+    return {
+        "gtin": gtin,
+        "name": str(name).strip(),
+        "brand": brand,
+        "category_path": map_category(raw),
+        "net_content_value": net_value,
+        "net_content_unit": net_unit,
+        "net_content_canonical": net_canonical,
+        "country_of_origin": (raw.get("countries") or "").split(",")[0].strip() or None,
+        "food": {
+            "ingredients_text": raw.get("ingredients_text") or None,
+            "allergens": _clean_tags(raw.get("allergens_tags")),
+            "additives": _clean_tags(raw.get("additives_tags")),
+            "nutriments": transform_nutriments(raw.get("nutriments") or {}),
+            "nutrition_basis": "per_100g",
+            "serving_size": raw.get("serving_size") or None,
+            "nutri_score": (raw.get("nutriscore_grade") or "").upper()[:1] or None,
+        },
+        "image_url": raw.get("image_front_url") or raw.get("image_url") or None,
+    }

ingestion/opengoods/jobs/seed_off.py

@@ -0,0 +1,66 @@
+"""Seed the database with Open Food Facts data.
+
+Usage:
+    # from a list of barcodes via the OFF API
+    python -m opengoods.jobs.seed_off --barcodes 3017624010701 5449000000996
+
+    # from a downloaded OFF JSONL dump (optionally .gz), limited to N records
+    python -m opengoods.jobs.seed_off --dump products.jsonl.gz --limit 1000
+
+The OFF read API is rate-limited client-side; for large imports use a dump.
+"""
+
+from __future__ import annotations
+
+import argparse
+import sys
+from collections.abc import Iterator
+
+import psycopg
+
+from opengoods.adapters.openfoodfacts import OpenFoodFactsAdapter, read_dump
+from opengoods.etl.load import default_dsn, ensure_source, load_record
+from opengoods.etl.transform import transform
+
+
+def _raw_records(args: argparse.Namespace) -> Iterator[dict]:
+    if args.dump:
+        records = read_dump(args.dump)
+    else:
+        adapter = OpenFoodFactsAdapter(min_interval=args.min_interval)
+        records = adapter.fetch(args.barcodes)
+    for i, rec in enumerate(records):
+        if args.limit and i >= args.limit:
+            break
+        yield rec
+
+
+def run(args: argparse.Namespace) -> int:
+    loaded = skipped = 0
+    with psycopg.connect(args.dsn, autocommit=False) as conn:
+        source_id = ensure_source(conn)
+        for raw in _raw_records(args):
+            rec = transform(raw)
+            if rec is None:
+                skipped += 1
+                continue
+            load_record(conn, rec, source_id, raw)
+            loaded += 1
+        conn.commit()
+    print(f"loaded={loaded} skipped={skipped}")
+    return 0
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description="Seed OpenGoods from Open Food Facts")
+    src = parser.add_mutually_exclusive_group(required=True)
+    src.add_argument("--barcodes", nargs="+", help="barcodes to fetch via the OFF API")
+    src.add_argument("--dump", help="path to an OFF JSONL dump (.jsonl or .jsonl.gz)")
+    parser.add_argument("--limit", type=int, default=0, help="max records to load (0 = all)")
+    parser.add_argument("--min-interval", type=float, default=4.0, help="API throttle seconds")
+    parser.add_argument("--dsn", default=default_dsn(), help="PostgreSQL DSN")
+    return run(parser.parse_args(argv))
+
+
+if __name__ == "__main__":
+    sys.exit(main())

ingestion/pyproject.toml

@@ -5,6 +5,7 @@ description = "OpenGoods (天工·商品标签) ingestion & ETL: collect product
 requires-python = ">=3.11"
 dependencies = [
     "httpx>=0.27",
+    "psycopg[binary]>=3.2",
 ]
 
 [project.optional-dependencies]

ingestion/tests/fixtures/off_product.json

@@ -0,0 +1,26 @@
+{
+  "code": "3017624010701",
+  "product_name": "Nutella",
+  "product_name_en": "Nutella hazelnut spread",
+  "brands": "Ferrero, Nutella",
+  "quantity": "400 g",
+  "countries": "France, China",
+  "categories": "Spreads, Hazelnut spreads, Chocolate spreads",
+  "categories_tags": ["en:spreads", "en:chocolate-spreads"],
+  "ingredients_text": "Sugar, palm oil, hazelnuts, cocoa, skimmed milk powder",
+  "allergens_tags": ["en:milk", "en:nuts"],
+  "additives_tags": ["en:e322"],
+  "serving_size": "15 g",
+  "nutriscore_grade": "e",
+  "image_front_url": "https://images.openfoodfacts.org/images/products/301/762/401/0701/front_en.jpg",
+  "nutriments": {
+    "energy-kj_100g": 2252,
+    "energy-kcal_100g": 539,
+    "fat_100g": 30.9,
+    "saturated-fat_100g": 10.6,
+    "carbohydrates_100g": 57.5,
+    "sugars_100g": 56.3,
+    "proteins_100g": 6.3,
+    "salt_100g": 0.107
+  }
+}

ingestion/tests/test_load_integration.py

@@ -0,0 +1,61 @@
+"""Integration test for the DB loader.
+
+Skipped automatically when no database is reachable (e.g. local runs without
+docker, or CI jobs without a postgres service). Requires migrations applied.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+
+from opengoods.etl.load import default_dsn, ensure_source, load_record
+from opengoods.etl.transform import transform
+
+psycopg = pytest.importorskip("psycopg")
+
+FIXTURE = json.loads((Path(__file__).parent / "fixtures" / "off_product.json").read_text())
+
+
+@pytest.fixture()
+def conn():
+    try:
+        c = psycopg.connect(default_dsn(), connect_timeout=3)
+    except psycopg.OperationalError as exc:  # pragma: no cover - env dependent
+        pytest.skip(f"no database available: {exc}")
+    # ensure schema present
+    has_product = c.execute("SELECT to_regclass('public.product') IS NOT NULL").fetchone()[0]
+    if not has_product:
+        c.close()
+        pytest.skip("migrations not applied")
+    yield c
+    c.rollback()
+    c.close()
+
+
+def test_load_record_roundtrip(conn):
+    source_id = ensure_source(conn)
+    rec = transform(FIXTURE)
+    product_id = load_record(conn, rec, source_id, FIXTURE)
+
+    row = conn.execute(
+        "SELECT name, gtin, net_content_unit FROM product WHERE id = %s", (product_id,)
+    ).fetchone()
+    assert row[0] == "Nutella"
+    assert row[1] == "3017624010701"
+    assert row[2] == "g"
+
+    nutri = conn.execute(
+        "SELECT nutriments ->> 'energy_kcal' FROM food_detail WHERE product_id = %s",
+        (product_id,),
+    ).fetchone()
+    assert nutri[0] == "539.0"
+
+    prov = conn.execute(
+        "SELECT count(*) FROM product_source WHERE product_id = %s", (product_id,)
+    ).fetchone()
+    assert prov[0] >= 1
+
+    conn.rollback()  # keep the test DB clean

ingestion/tests/test_transform.py

@@ -0,0 +1,67 @@
+import json
+from decimal import Decimal
+from pathlib import Path
+
+import pytest
+
+from opengoods.etl.transform import (
+    is_valid_gtin,
+    map_category,
+    parse_quantity,
+    transform,
+    transform_nutriments,
+)
+
+FIXTURE = json.loads((Path(__file__).parent / "fixtures" / "off_product.json").read_text())
+
+
+def test_is_valid_gtin():
+    assert is_valid_gtin("3017624010701")  # real EAN-13
+    assert is_valid_gtin("5449000000996")  # Coca-Cola
+    assert not is_valid_gtin("3017624010700")  # bad check digit
+    assert not is_valid_gtin("123")
+    assert not is_valid_gtin("notanumber")
+
+
+def test_parse_quantity():
+    assert parse_quantity("400 g") == (Decimal("400"), "g")
+    assert parse_quantity("1,5 L") == (Decimal("1.5"), "L")
+    assert parse_quantity("") is None
+    assert parse_quantity("family size") is None
+
+
+def test_map_category():
+    assert map_category({"product_name": "Spring Water"}) == "food.beverages.water"
+    assert map_category({"categories": "Dark chocolate"}) == "food.snacks.chocolate"
+    assert map_category({"product_name": "Mystery"}) is None
+
+
+def test_transform_nutriments_dual_energy():
+    out = transform_nutriments(FIXTURE["nutriments"])
+    assert out["energy_kj"] == 2252.0
+    assert out["energy_kcal"] == 539.0
+    assert out["fat"] == 30.9
+    assert out["salt"] == 0.107
+
+
+def test_transform_nutriments_fills_missing_energy():
+    out = transform_nutriments({"energy-kcal_100g": 100})
+    assert out["energy_kj"] == pytest.approx(418.4)
+
+
+def test_transform_full_record():
+    rec = transform(FIXTURE)
+    assert rec is not None
+    assert rec["gtin"] == "3017624010701"
+    assert rec["name"] == "Nutella"
+    assert rec["brand"] == "Ferrero"
+    assert rec["net_content_unit"] == "g"
+    assert rec["net_content_canonical"] == Decimal("400")
+    assert rec["country_of_origin"] == "France"
+    assert rec["food"]["nutri_score"] == "E"
+    assert "milk" in rec["food"]["allergens"]
+    assert rec["image_url"].endswith(".jpg")
+
+
+def test_transform_drops_unnamed():
+    assert transform({"code": "0000000000000"}) is None

migrations/0001_init.down.sql

@@ -0,0 +1,21 @@
+DROP TRIGGER IF EXISTS trg_product_sync ON product;
+DROP FUNCTION IF EXISTS product_sync_tsv();
+
+DROP TABLE IF EXISTS merge_log;
+DROP TABLE IF EXISTS product_source;
+DROP TABLE IF EXISTS product_image;
+DROP TABLE IF EXISTS product_msrp;
+DROP TABLE IF EXISTS food_detail;
+DROP TABLE IF EXISTS product;
+DROP TABLE IF EXISTS attribute_definition;
+DROP TABLE IF EXISTS unit;
+DROP TABLE IF EXISTS category_schema;
+DROP TABLE IF EXISTS category;
+DROP TABLE IF EXISTS manufacturer;
+DROP TABLE IF EXISTS brand;
+DROP TABLE IF EXISTS source;
+
+DROP EXTENSION IF EXISTS ltree;
+DROP EXTENSION IF EXISTS pg_trgm;
+-- keep pgcrypto (commonly shared); drop only if you are sure:
+-- DROP EXTENSION IF EXISTS pgcrypto;

migrations/0001_init.up.sql

@@ -0,0 +1,182 @@
+-- OpenGoods (天工·商品标签) initial schema.
+-- Public-good product information store: facts only, no commerce.
+
+CREATE EXTENSION IF NOT EXISTS pgcrypto;   -- gen_random_uuid()
+CREATE EXTENSION IF NOT EXISTS pg_trgm;     -- fuzzy name search
+CREATE EXTENSION IF NOT EXISTS ltree;       -- category subtree queries
+
+-- Data sources (Open Food Facts / USDA / GS1 ...) with trust + license.
+CREATE TABLE source (
+    id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name         TEXT NOT NULL,
+    homepage     TEXT,
+    license      TEXT,
+    trust_weight NUMERIC(3,2) NOT NULL DEFAULT 0.5,
+    notes        TEXT,
+    UNIQUE (name)
+);
+
+CREATE TABLE brand (
+    id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name            TEXT NOT NULL,
+    normalized_name TEXT NOT NULL,
+    aliases         TEXT[] NOT NULL DEFAULT '{}',
+    UNIQUE (normalized_name)
+);
+
+CREATE TABLE manufacturer (
+    id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name            TEXT NOT NULL,
+    normalized_name TEXT NOT NULL,
+    country         VARCHAR(64),
+    UNIQUE (normalized_name)
+);
+
+-- Self-built category tree, each node optionally mapped to a GS1 GPC brick.
+CREATE TABLE category (
+    id             UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name_zh        TEXT NOT NULL,
+    name_en        TEXT,
+    parent_id      UUID REFERENCES category(id),
+    path           LTREE NOT NULL,
+    gpc_brick_code VARCHAR(10),
+    level          INT NOT NULL DEFAULT 0,
+    UNIQUE (path)
+);
+
+-- Parameter template / constraints per category.
+CREATE TABLE category_schema (
+    category_id           UUID PRIMARY KEY REFERENCES category(id) ON DELETE CASCADE,
+    required_attributes   TEXT[] NOT NULL DEFAULT '{}',
+    recommended_attributes TEXT[] NOT NULL DEFAULT '{}',
+    nutriment_basis       VARCHAR(16)
+);
+
+-- Unit dictionary: each unit maps to a canonical unit within its dimension.
+CREATE TABLE unit (
+    code                VARCHAR(16) PRIMARY KEY,
+    dimension           VARCHAR(16) NOT NULL,
+    canonical           VARCHAR(16) NOT NULL,
+    to_canonical_factor NUMERIC,
+    aliases             TEXT[] NOT NULL DEFAULT '{}',
+    display             TEXT
+);
+
+-- Parameter dictionary: standard attribute keys with default unit.
+CREATE TABLE attribute_definition (
+    key          VARCHAR(64) PRIMARY KEY,
+    label_zh     TEXT,
+    label_en     TEXT,
+    dimension    VARCHAR(16),
+    default_unit VARCHAR(16) REFERENCES unit(code),
+    aliases      TEXT[] NOT NULL DEFAULT '{}'
+);
+
+CREATE TABLE product (
+    id                    UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    gtin                  VARCHAR(14),
+    name                  TEXT NOT NULL,
+    brand_id              UUID REFERENCES brand(id),
+    manufacturer_id       UUID REFERENCES manufacturer(id),
+    category_id           UUID REFERENCES category(id),
+    gpc_brick_code        VARCHAR(10),
+    net_content_value     NUMERIC,
+    net_content_unit      VARCHAR(16),
+    net_content_canonical NUMERIC,
+    country_of_origin     VARCHAR(64),
+    shelf_life_days       INT,
+    storage               TEXT,
+    attributes            JSONB NOT NULL DEFAULT '{}',
+    quality_score         NUMERIC(4,3) NOT NULL DEFAULT 0,
+    status                VARCHAR(16) NOT NULL DEFAULT 'active',
+    canonical_id          UUID REFERENCES product(id),
+    search_tsv            TSVECTOR,
+    created_at            TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at            TIMESTAMPTZ NOT NULL DEFAULT now(),
+    CONSTRAINT product_status_chk CHECK (status IN ('active','merged','deprecated')),
+    CONSTRAINT product_quality_chk CHECK (quality_score >= 0 AND quality_score <= 1)
+);
+
+CREATE TABLE food_detail (
+    product_id       UUID PRIMARY KEY REFERENCES product(id) ON DELETE CASCADE,
+    ingredients_text TEXT,
+    ingredients      JSONB,
+    allergens        TEXT[] NOT NULL DEFAULT '{}',
+    additives        TEXT[] NOT NULL DEFAULT '{}',
+    nutriments       JSONB,
+    nutrition_basis  VARCHAR(16),
+    serving_size     VARCHAR(32),
+    nutri_score      CHAR(1),
+    labels           TEXT[] NOT NULL DEFAULT '{}',
+    CONSTRAINT food_basis_chk CHECK (nutrition_basis IS NULL OR nutrition_basis IN ('per_100g','per_100ml','per_serving'))
+);
+
+-- Official manufacturer-suggested retail price snapshot (no purchase link).
+CREATE TABLE product_msrp (
+    id             UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    product_id     UUID NOT NULL REFERENCES product(id) ON DELETE CASCADE,
+    amount         NUMERIC(12,2) NOT NULL,
+    currency       CHAR(3) NOT NULL,
+    region         VARCHAR(8) NOT NULL DEFAULT 'CN',
+    source_id      UUID REFERENCES source(id),
+    source_url     TEXT,
+    effective_date DATE,
+    note           TEXT,
+    created_at     TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE product_image (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    product_id UUID NOT NULL REFERENCES product(id) ON DELETE CASCADE,
+    url        TEXT NOT NULL,
+    kind       VARCHAR(16) NOT NULL DEFAULT 'other',
+    license    TEXT,
+    source_id  UUID REFERENCES source(id),
+    CONSTRAINT image_kind_chk CHECK (kind IN ('front','ingredients','nutrition','other'))
+);
+
+-- Field-level provenance: which source provided which fields.
+CREATE TABLE product_source (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    product_id UUID NOT NULL REFERENCES product(id) ON DELETE CASCADE,
+    source_id  UUID REFERENCES source(id),
+    url        TEXT,
+    fields     TEXT[] NOT NULL DEFAULT '{}',
+    fetched_at TIMESTAMPTZ,
+    raw        JSONB
+);
+
+CREATE TABLE merge_log (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    kept_id    UUID,
+    merged_id  UUID,
+    reason     TEXT,
+    actor      TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- Indexes
+CREATE UNIQUE INDEX idx_product_gtin ON product (gtin) WHERE gtin IS NOT NULL;
+CREATE INDEX idx_product_name_trgm ON product USING gin (name gin_trgm_ops);
+CREATE INDEX idx_product_attrs ON product USING gin (attributes);
+CREATE INDEX idx_product_tsv ON product USING gin (search_tsv);
+CREATE INDEX idx_product_category ON product (category_id);
+CREATE INDEX idx_product_brand ON product (brand_id);
+CREATE INDEX idx_product_updated ON product (updated_at);
+CREATE INDEX idx_food_nutriments ON food_detail USING gin (nutriments);
+CREATE INDEX idx_category_path ON category USING gist (path);
+CREATE INDEX idx_msrp_product ON product_msrp (product_id);
+CREATE INDEX idx_psource_product ON product_source (product_id);
+
+-- Keep search_tsv and updated_at in sync.
+CREATE OR REPLACE FUNCTION product_sync_tsv() RETURNS trigger AS $$
+BEGIN
+    NEW.search_tsv := to_tsvector('simple', coalesce(NEW.name, ''));
+    NEW.updated_at := now();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER trg_product_sync
+    BEFORE INSERT OR UPDATE ON product
+    FOR EACH ROW EXECUTE FUNCTION product_sync_tsv();

migrations/0002_seed_units.down.sql

@@ -0,0 +1,2 @@
+DELETE FROM attribute_definition;
+DELETE FROM unit;

migrations/0002_seed_units.up.sql

@@ -0,0 +1,29 @@
+-- Unit dictionary seed. Keep factors aligned with ingestion/opengoods/units.py.
+
+INSERT INTO unit (code, dimension, canonical, to_canonical_factor, aliases, display) VALUES
+    ('mg',   'mass',     'g',   0.001,  ARRAY['毫克'],                 'mg'),
+    ('g',    'mass',     'g',   1,      ARRAY['克','gram','grams'],    'g'),
+    ('kg',   'mass',     'g',   1000,   ARRAY['kgs','千克','公斤'],     'kg'),
+    ('ml',   'volume',   'ml',  1,      ARRAY['毫升','milliliter'],     'mL'),
+    ('cl',   'volume',   'ml',  10,     ARRAY['厘升'],                 'cL'),
+    ('l',    'volume',   'ml',  1000,   ARRAY['L','升','litre','liter'], 'L'),
+    ('kj',   'energy',   'kJ',  1,      ARRAY['kJ','千焦'],            'kJ'),
+    ('kcal', 'energy',   'kJ',  4.184,  ARRAY['千卡','大卡'],          'kcal'),
+    ('pct',  'ratio',    'pct', 1,      ARRAY['%','percent','百分比'],  '%'),
+    ('unit', 'count',    'unit',1,      ARRAY['个','件','pcs','piece'], '个'),
+    ('mm',   'length',   'mm',  1,      ARRAY['毫米'],                 'mm'),
+    ('cm',   'length',   'mm',  10,     ARRAY['厘米'],                 'cm'),
+    ('day',  'duration', 'day', 1,      ARRAY['天','日','days'],        'day')
+ON CONFLICT (code) DO NOTHING;
+
+-- A few common food attribute definitions referencing the unit dictionary.
+INSERT INTO attribute_definition (key, label_zh, label_en, dimension, default_unit, aliases) VALUES
+    ('energy',        '能量',   'Energy',        'energy', 'kj',   ARRAY['energy_kj']),
+    ('proteins',      '蛋白质', 'Proteins',      'mass',   'g',    ARRAY['protein']),
+    ('fat',           '脂肪',   'Fat',           'mass',   'g',    ARRAY['fats']),
+    ('saturated_fat', '饱和脂肪','Saturated fat','mass',   'g',    ARRAY['saturated-fat']),
+    ('carbohydrates', '碳水化合物','Carbohydrates','mass', 'g',    ARRAY['carbs']),
+    ('sugars',        '糖',     'Sugars',        'mass',   'g',    ARRAY['sugar']),
+    ('salt',          '盐',     'Salt',          'mass',   'g',    ARRAY['sodium_salt']),
+    ('net_content',   '净含量', 'Net content',   NULL,     NULL,   ARRAY['quantity'])
+ON CONFLICT (key) DO NOTHING;

migrations/0003_seed_categories.down.sql

@@ -0,0 +1,3 @@
+-- remove seeded categories (children first via path depth)
+DELETE FROM category_schema;
+DELETE FROM category;

migrations/0003_seed_categories.up.sql

@@ -0,0 +1,53 @@
+-- Seed a FOOD-focused category skeleton.
+-- Structure = GS1 GPC backbone (segment/family/class) mapped to a self-built
+-- Chinese tree. ltree labels are english slugs (ltree forbids spaces/CJK);
+-- Chinese names live in name_zh. gpc_brick_code on leaves is a representative
+-- starter value to be replaced by a full official GPC import later.
+
+-- Root segment: Food/Beverage/Tobacco (GPC segment 50000000)
+INSERT INTO category (name_zh, name_en, parent_id, path, gpc_brick_code, level)
+VALUES ('食品饮料', 'Food/Beverage', NULL, 'food', '50000000', 0);
+
+-- Families (level 1)
+INSERT INTO category (name_zh, name_en, parent_id, path, gpc_brick_code, level)
+SELECT v.name_zh, v.name_en, c.id, v.path::ltree, v.code, 1
+FROM (VALUES
+    ('饮料',     'Beverages',        'food.beverages',  '50130000'),
+    ('乳制品蛋类','Dairy/Eggs',       'food.dairy',      '50180000'),
+    ('烘焙',     'Bakery',           'food.bakery',     '50100000'),
+    ('零食',     'Snacks',           'food.snacks',     '50190000'),
+    ('粮油',     'Staples/Oils',     'food.staple',     '50160000'),
+    ('调味品',   'Condiments',       'food.condiments', '50170000')
+) AS v(name_zh, name_en, path, code)
+JOIN category c ON c.path = 'food';
+
+-- Classes / leaves (level 2) with representative GPC brick codes
+INSERT INTO category (name_zh, name_en, parent_id, path, gpc_brick_code, level)
+SELECT v.name_zh, v.name_en, c.id, v.path::ltree, v.code, 2
+FROM (VALUES
+    ('包装饮用水', 'Bottled water',   'food.beverages.water',      '10000224', 'food.beverages'),
+    ('碳酸饮料',   'Carbonated',      'food.beverages.carbonated', '10000225', 'food.beverages'),
+    ('果汁',       'Juice',           'food.beverages.juice',      '10000226', 'food.beverages'),
+    ('牛奶',       'Milk',            'food.dairy.milk',           '10000158', 'food.dairy'),
+    ('酸奶',       'Yogurt',          'food.dairy.yogurt',         '10000159', 'food.dairy'),
+    ('奶酪',       'Cheese',          'food.dairy.cheese',         '10000160', 'food.dairy'),
+    ('面包',       'Bread',           'food.bakery.bread',         '10000040', 'food.bakery'),
+    ('饼干',       'Biscuits',        'food.bakery.biscuits',      '10000041', 'food.bakery'),
+    ('薯片膨化',   'Chips/Snacks',    'food.snacks.chips',         '10000310', 'food.snacks'),
+    ('巧克力',     'Chocolate',       'food.snacks.chocolate',     '10000311', 'food.snacks'),
+    ('大米',       'Rice',            'food.staple.rice',          '10000500', 'food.staple'),
+    ('面条',       'Noodles',         'food.staple.noodles',       '10000501', 'food.staple'),
+    ('食用油',     'Cooking oil',     'food.staple.cooking_oil',   '10000502', 'food.staple'),
+    ('酱油',       'Soy sauce',       'food.condiments.soy_sauce', '10000600', 'food.condiments'),
+    ('食盐',       'Table salt',      'food.condiments.salt',      '10000601', 'food.condiments')
+) AS v(name_zh, name_en, path, code, parent_path)
+JOIN category c ON c.path = v.parent_path::ltree;
+
+-- Parameter templates: leaf food categories use per_100g/ml nutrition basis.
+INSERT INTO category_schema (category_id, required_attributes, recommended_attributes, nutriment_basis)
+SELECT id,
+       ARRAY['net_content'],
+       ARRAY['energy','proteins','fat','carbohydrates','sugars','salt'],
+       CASE WHEN path <@ 'food.beverages' THEN 'per_100ml' ELSE 'per_100g' END
+FROM category
+WHERE level = 2;

migrations/README.md

@@ -1,3 +1,28 @@
 # Database migrations (golang-migrate)
 
-SQL migrations live here from milestone M1. Format: `NNNN_description.up.sql` / `.down.sql`.
+SQL migrations for the OpenGoods database, applied with
+[golang-migrate](https://github.com/golang-migrate/migrate).
+Naming: `NNNN_description.up.sql` / `NNNN_description.down.sql`.
+
+## Files
+| Version | Up | 内容 |
+|---------|----|------|
+| 0001 | `0001_init` | 扩展(pgcrypto/pg_trgm/ltree) + 全部核心表 + 索引 + tsvector 触发器 |
+| 0002 | `0002_seed_units` | 单位字典（与 `ingestion/opengoods/units.py` 一致）+ 常用营养参数定义 |
+| 0003 | `0003_seed_categories` | 食品品类骨架（GS1 GPC 映射 + 自建中文树）+ 品类参数模板 |
+
+## 运行
+
+先起本地依赖：`docker compose up -d postgres`
+
+```bash
+export DBURL="postgres://opengoods:opengoods@localhost:5432/opengoods?sslmode=disable"
+migrate -path migrations -database "$DBURL" up        # 升级到最新
+migrate -path migrations -database "$DBURL" down -all # 全部回滚
+migrate -path migrations -database "$DBURL" version   # 查看当前版本
+```
+
+安装 CLI：`go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate@v4.18.1`
+
+> ltree 标签为英文 slug（不支持空格/中文），中文名存于 `category.name_zh`。
+> `gpc_brick_code` 为食品子集的代表值，后续用官方 GPC 全量导入替换。