fix: 恢复并发 SKU 规格唯一键冲突 (#283)

admin/repository/catalog_import.go

@@ -336,10 +336,23 @@ func findCatalogSKUBySpec(q Execer, goodsID, specKey string) (*catalogSKUStored,
 	return scanCatalogSKU(q.QueryRow(`SELECT sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,source_observed_at,field_sources,field_observed_at FROM shopee_skus WHERE goods_id=? AND spec_key=?`, goodsID, specKey))
 }
 
+func findCatalogSKUBySpecForUpdate(q Execer, goodsID, specKey string) (*catalogSKUStored, error) {
+	// 规格唯一键冲突后必须使用当前读。普通 SELECT 在 MySQL 默认的
+	// REPEATABLE READ 事务中会继续使用第一次查询的快照，看不到竞争方
+	// 刚刚提交的 SKU，导致无法恢复本来可幂等的并发写入。
+	return scanCatalogSKU(q.QueryRow(`SELECT sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,source_observed_at,field_sources,field_observed_at FROM shopee_skus WHERE goods_id=? AND spec_key=? FOR UPDATE`, goodsID, specKey))
+}
+
 func findCatalogSKUByExternalID(q Execer, skuID string) (*catalogSKUStored, error) {
 	return scanCatalogSKU(q.QueryRow(`SELECT sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,source_observed_at,field_sources,field_observed_at FROM shopee_skus WHERE shopee_sku_id=?`, skuID))
 }
 
+func isShopeeSKUSpecUniqueConflict(err error) bool {
+	var mysqlErr *mysql.MySQLError
+	return errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 &&
+		strings.Contains(mysqlErr.Message, "uq_shopee_skus_spec")
+}
+
 // UpsertCatalogShopeeSKU 用真实 ID 或商品规格身份定位同一内部记录，人工行永不覆盖。
 func UpsertCatalogShopeeSKU(q Execer, in CatalogShopeeSKUInput) (CatalogSKUOutcome, error) {
 	bySpec, err := findCatalogSKUBySpec(q, in.GoodsID, in.SpecKey)
@@ -372,10 +385,23 @@ func UpsertCatalogShopeeSKU(q Execer, in CatalogShopeeSKUInput) (CatalogSKUOutco
 		sourcesJSON, _ := json.Marshal(fieldSources)
 		timesJSON, _ := json.Marshal(fieldTimes)
 		_, err = q.Exec(`INSERT INTO shopee_skus(sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,field_sources,field_observed_at,source_observed_at,created_at,updated_at) VALUES(?,NULLIF(?,''),?,?,?,NULLIF(?,''),NULLIF(?,''),NULLIF(?,''),?,NULLIF(?,''),0,?,?,?,?,?,?)`, in.RecordID, in.ShopeeSKUID, in.GoodsID, in.SpecRaw, in.SpecKey, in.Color, in.Size, in.Advice, parse, in.SKUCode, in.Source, string(sourcesJSON), string(timesJSON), in.ObservedAt, in.Now, in.Now)
-		if err != nil {
+		if err == nil {
+			return CatalogSKUCreated, nil
+		}
+		if !isShopeeSKUSpecUniqueConflict(err) {
 			return "", err
 		}
-		return CatalogSKUCreated, nil
+
+		// 目录导入和 SYB 同步可以同时写同一个规格。唯一键已经证明竞争方
+		// 已提交该业务身份；重新读取后沿用下面原有的来源优先级规则，不能
+		// 把它当成同步失败，也不能用 INSERT IGNORE 静默跳过字段补全。
+		current, err = findCatalogSKUBySpecForUpdate(q, in.GoodsID, in.SpecKey)
+		if err != nil {
+			return "", fmt.Errorf("规格唯一键冲突后重读商品 %s 的 SKU 失败: %w", in.GoodsID, err)
+		}
+		if current == nil {
+			return "", fmt.Errorf("规格唯一键冲突后未找到商品 %s 的规格 %s", in.GoodsID, in.SpecKey)
+		}
 	}
 	if current.ShopeeSKUID.Valid && in.ShopeeSKUID != "" && current.ShopeeSKUID.String != in.ShopeeSKUID {
 		return "", fmt.Errorf("商品 %s 的规格 %s 已对应真实蝦皮 SKU %s", in.GoodsID, in.SpecRaw, current.ShopeeSKUID.String)

admin/repository/catalog_import_test.go

@@ -4,13 +4,96 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"strings"
 	"testing"
 
+	"github.com/go-sql-driver/mysql"
 	_ "modernc.org/sqlite"
 
 	"cmautobuy/admin/model"
 )
 
+type skuSpecConflictExecer struct {
+	*sql.DB
+	conflictKey string
+	inserted    bool
+}
+
+func (q *skuSpecConflictExecer) Exec(query string, args ...any) (sql.Result, error) {
+	if !q.inserted && strings.HasPrefix(strings.TrimSpace(query), "INSERT INTO shopee_skus") {
+		q.inserted = true
+		_, err := q.DB.Exec(`INSERT INTO shopee_skus(
+			sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,is_manual,
+			source,field_sources,field_observed_at,source_observed_at,created_at,updated_at
+		) VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`,
+			"catalog:existing", "GOODS-1", "白色,M", "白色,M", "目录白", "M", "",
+			1, 0, "xlsx-processed", `{"color":"xlsx-processed","size":"xlsx-processed","advice":"","sku_code":""}`,
+			`{"color":"2026-08-21T00:00:00Z","size":"2026-08-21T00:00:00Z","advice":"","sku_code":""}`,
+			"2026-08-21T00:00:00Z", "2026-08-21T00:00:00Z", "2026-08-21T00:00:00Z")
+		if err != nil {
+			return nil, err
+		}
+		return nil, &mysql.MySQLError{Number: 1062, Message: "Duplicate entry for key '" + q.conflictKey + "'"}
+	}
+	return q.DB.Exec(query, args...)
+}
+
+func (q *skuSpecConflictExecer) QueryRow(query string, args ...any) *sql.Row {
+	return q.DB.QueryRow(strings.TrimSuffix(query, " FOR UPDATE"), args...)
+}
+
+func newSKUConflictTestDB(t *testing.T, conflictKey string) *skuSpecConflictExecer {
+	t.Helper()
+	db, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { db.Close() })
+	if _, err := db.Exec(`CREATE TABLE shopee_skus (
+		sku_id TEXT PRIMARY KEY, shopee_sku_id TEXT, goods_id TEXT NOT NULL,
+		spec_raw TEXT NOT NULL, spec_key TEXT NOT NULL, color TEXT, size TEXT,
+		advice TEXT, parse_ok INTEGER NOT NULL, sku_code TEXT, is_manual INTEGER NOT NULL,
+		source TEXT, field_sources TEXT, field_observed_at TEXT, source_observed_at TEXT,
+		created_at TEXT NOT NULL, updated_at TEXT NOT NULL,
+		UNIQUE(goods_id, spec_key)
+	)`); err != nil {
+		t.Fatal(err)
+	}
+	return &skuSpecConflictExecer{DB: db, conflictKey: conflictKey}
+}
+
+func TestUpsertCatalogShopeeSKU_规格唯一键并发冲突后安全重读(t *testing.T) {
+	q := newSKUConflictTestDB(t, "uq_shopee_skus_spec")
+	outcome, err := UpsertCatalogShopeeSKU(q, CatalogShopeeSKUInput{
+		RecordID: "syb:incoming", GoodsID: "GOODS-1", SpecRaw: "白色,M", SpecKey: "白色,M",
+		Color: "顺运宝白", Size: "M", ParseOK: true, Source: "syb",
+		ObservedAt: "2026-08-21T00:01:00Z", Now: "2026-08-21T00:01:00Z", UpdatePolicy: "fill_missing",
+	})
+	if err != nil || outcome != CatalogSKUSkipped {
+		t.Fatalf("并发撞键后应重读并按既有规则跳过：outcome=%q err=%v", outcome, err)
+	}
+	var id, color, source string
+	if err := q.QueryRow(`SELECT sku_id,color,source FROM shopee_skus WHERE goods_id='GOODS-1' AND spec_key='白色,M'`).Scan(&id, &color, &source); err != nil {
+		t.Fatal(err)
+	}
+	if id != "catalog:existing" || color != "目录白" || source != "xlsx-processed" {
+		t.Fatalf("竞争方目录数据不得被 SYB 覆盖：id=%q color=%q source=%q", id, color, source)
+	}
+}
+
+func TestUpsertCatalogShopeeSKU_非规格唯一键冲突仍失败(t *testing.T) {
+	q := newSKUConflictTestDB(t, "uq_shopee_skus_external")
+	_, err := UpsertCatalogShopeeSKU(q, CatalogShopeeSKUInput{
+		RecordID: "syb:incoming", GoodsID: "GOODS-1", SpecRaw: "白色,M", SpecKey: "白色,M",
+		Color: "顺运宝白", Size: "M", ParseOK: true, Source: "syb",
+		ObservedAt: "2026-08-21T00:01:00Z", Now: "2026-08-21T00:01:00Z", UpdatePolicy: "fill_missing",
+	})
+	var mysqlErr *mysql.MySQLError
+	if !errors.As(err, &mysqlErr) || mysqlErr.Number != 1062 {
+		t.Fatalf("非规格唯一键冲突必须原样失败：%v", err)
+	}
+}
+
 func TestCatalogImportRun_登记查询重放和冲突(t *testing.T) {
 	db, err := sql.Open("sqlite", ":memory:")
 	if err != nil {