diff --git a/internal/repository/warehouse.go b/internal/repository/warehouse.go
index cbc29a4f..58a74b44 100644
--- a/internal/repository/warehouse.go
+++ b/internal/repository/warehouse.go
@@ -2,11 +2,17 @@ package repository
 
 import (
 	"database/sql"
+	"errors"
 
 	"github.com/wmms/wmms/internal/model"
 	"github.com/wmms/wmms/pkg/database"
 )
 
+// ErrWarehouseNotFound 表示仓库 id 不存在，或这条仓库不属于当前组织。
+// 建库位时的 INSERT...SELECT 影响 0 行就是这种情况，接口据此回错，
+// 而不是把「没写成」报成"创建成功"。
+var ErrWarehouseNotFound = errors.New("仓库不存在，可能已被删除或不属于当前组织")
+
 type WarehouseRepository struct{}
 
 func NewWarehouseRepository() *WarehouseRepository { return &WarehouseRepository{} }
@@ -58,11 +64,25 @@ func (r *WarehouseRepository) Update(item *model.Warehouse) error {
 }
 
 func (r *WarehouseRepository) CreateLocation(item *model.WarehouseLocation, organizationID int64) error {
+	// 仓库归属条件写在 SELECT 里，避免「先查后插」之间的竞态。
+	//
+	// 匹配不到仓库时这条语句影响 0 行，但 MySQL 不报错：err 为 nil，LastInsertId()
+	// 返回 0。此前只看 err，接口回 201「创建成功」而库里一行都没有（实测请求前后
+	// warehouse_locations 行数都是 1，刷新后库位消失）。所以这里和按主键更新一样，
+	// 以 RowsAffected 为准——INSERT 的 RowsAffected 就是实际插入行数，不受
+	// clientFoundRows 影响。
 	result, err := database.DB.Exec(`INSERT INTO warehouse_locations (warehouse_id, code, name, status)
 		SELECT id, ?, ?, ? FROM warehouses WHERE id = ? AND organization_id = ?`, item.Code, item.Name, item.Status, item.WarehouseID, organizationID)
 	if err != nil {
 		return err
 	}
+	affected, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if affected == 0 {
+		return ErrWarehouseNotFound
+	}
 	item.ID, err = result.LastInsertId()
 	return err
 }
diff --git a/internal/repository/warehouse_test.go b/internal/repository/warehouse_test.go
new file mode 100644
index 00000000..0dd97aa6
--- /dev/null
+++ b/internal/repository/warehouse_test.go
@@ -0,0 +1,68 @@
+package repository
+
+import (
+	"errors"
+	"regexp"
+	"testing"
+
+	"github.com/DATA-DOG/go-sqlmock"
+	"github.com/wmms/wmms/internal/model"
+	"github.com/wmms/wmms/pkg/database"
+)
+
+// 与 warehouse.go 里的语句逐字一致：换行和缩进都参与匹配。
+const createLocationSQL = `INSERT INTO warehouse_locations (warehouse_id, code, name, status)
+		SELECT id, ?, ?, ? FROM warehouses WHERE id = ? AND organization_id = ?`
+
+func newWarehouseMock(t *testing.T) sqlmock.Sqlmock {
+	t.Helper()
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("open sql mock: %v", err)
+	}
+	t.Cleanup(func() { database.DB = nil; db.Close() })
+	database.DB = db
+	return mock
+}
+
+// 仓库不存在时（id 打错、仓库已被删、或这条仓库属于别的组织）这条 INSERT...SELECT
+// 影响 0 行，而 MySQL 既不报错、LastInsertId() 也只回 0。此前只看 err，接口会回
+// 201「Location created successfully」，库里却没有新行，刷新后库位消失、重试还是
+// "成功"（实测请求前后 warehouse_locations 行数都是 1）。
+func TestCreateLocationReportsMissingWarehouse(t *testing.T) {
+	mock := newWarehouseMock(t)
+	mock.ExpectExec(regexp.QuoteMeta(createLocationSQL)).
+		WithArgs("L1", "库位一", "active", int64(999), int64(1)).
+		WillReturnResult(sqlmock.NewResult(0, 0))
+
+	item := &model.WarehouseLocation{WarehouseID: 999, Code: "L1", Name: "库位一", Status: "active"}
+	err := NewWarehouseRepository().CreateLocation(item, 1)
+	if !errors.Is(err, ErrWarehouseNotFound) {
+		t.Fatalf("影响 0 行应当返回 ErrWarehouseNotFound，实际 %v", err)
+	}
+	if item.ID != 0 {
+		t.Fatalf("没插进去就不该有 id，实际 %d", item.ID)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// 反面：真的插进去了就必须回填 id，别把成功路径也一起判成失败。
+func TestCreateLocationReturnsInsertedID(t *testing.T) {
+	mock := newWarehouseMock(t)
+	mock.ExpectExec(regexp.QuoteMeta(createLocationSQL)).
+		WithArgs("L1", "库位一", "active", int64(3), int64(1)).
+		WillReturnResult(sqlmock.NewResult(7, 1))
+
+	item := &model.WarehouseLocation{WarehouseID: 3, Code: "L1", Name: "库位一", Status: "active"}
+	if err := NewWarehouseRepository().CreateLocation(item, 1); err != nil {
+		t.Fatalf("插入成功不应报错，实际 %v", err)
+	}
+	if item.ID != 7 {
+		t.Fatalf("应当回填自增 id 7，实际 %d", item.ID)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatal(err)
+	}
+}