feat: 添加购买分组功能，替代跨分类购物选项

backend/internal/api/handlers/product.go

@@ -49,17 +49,17 @@ func (h *CategoryHandler) Create(c *gin.Context) {
 	}
 
 	category := models.Category{
-		Name:               req.Name,
-		Description:        req.Description,
-		ParentID:           req.ParentID,
-		MinAmount:          req.MinAmount,
-		MaxAmount:          req.MaxAmount,
-		MinQuantity:        req.MinQuantity,
-		MaxQuantity:        req.MaxQuantity,
-		MinWeight:          req.MinWeight,
-		MaxWeight:          req.MaxWeight,
-		AllowCrossCategory: req.AllowCrossCategory != nil && *req.AllowCrossCategory,
-		SortOrder:          req.SortOrder,
+		Name:             req.Name,
+		Description:      req.Description,
+		ParentID:         req.ParentID,
+		PurchaseGroupID:  req.PurchaseGroupID,
+		MinAmount:        req.MinAmount,
+		MaxAmount:        req.MaxAmount,
+		MinQuantity:      req.MinQuantity,
+		MaxQuantity:      req.MaxQuantity,
+		MinWeight:        req.MinWeight,
+		MaxWeight:        req.MaxWeight,
+		SortOrder:        req.SortOrder,
 	}
 
 	if err := utils.DB.Create(&category).Error; err != nil {
@@ -123,8 +123,8 @@ func (h *CategoryHandler) Update(c *gin.Context) {
 	if req.SortOrder != nil {
 		updates["sort_order"] = *req.SortOrder
 	}
-	if req.AllowCrossCategory != nil {
-		updates["allow_cross_category"] = *req.AllowCrossCategory
+	if req.PurchaseGroupID != nil {
+		updates["purchase_group_id"] = *req.PurchaseGroupID
 	}
 
 	utils.DB.Model(&category).Updates(updates)

backend/internal/api/handlers/purchase_group.go

@@ -0,0 +1,105 @@
+package handlers
+
+import (
+	"net/http"
+	"strconv"
+
+	"sale/internal/models"
+	"sale/internal/schemas"
+	"sale/internal/utils"
+
+	"github.com/gin-gonic/gin"
+)
+
+type PurchaseGroupHandler struct{}
+
+func NewPurchaseGroupHandler() *PurchaseGroupHandler {
+	return &PurchaseGroupHandler{}
+}
+
+func (h *PurchaseGroupHandler) List(c *gin.Context) {
+	var groups []models.PurchaseGroup
+	utils.DB.Order("sort_order ASC, id ASC").Preload("Categories").Find(&groups)
+	c.JSON(http.StatusOK, gin.H{"data": groups})
+}
+
+func (h *PurchaseGroupHandler) Create(c *gin.Context) {
+	var req schemas.CreatePurchaseGroupRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	var existing models.PurchaseGroup
+	if err := utils.DB.Where("name = ?", req.Name).First(&existing).Error; err == nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "分组名称已存在"})
+		return
+	}
+
+	group := models.PurchaseGroup{
+		Name:        req.Name,
+		Description: req.Description,
+		SortOrder:   req.SortOrder,
+	}
+
+	if err := utils.DB.Create(&group).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create purchase group"})
+		return
+	}
+
+	c.JSON(http.StatusCreated, gin.H{"data": group})
+}
+
+func (h *PurchaseGroupHandler) Update(c *gin.Context) {
+	id, _ := strconv.Atoi(c.Param("id"))
+	var group models.PurchaseGroup
+	if err := utils.DB.First(&group, id).Error; err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Purchase group not found"})
+		return
+	}
+
+	var req schemas.UpdatePurchaseGroupRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	if req.Name != nil && *req.Name != group.Name {
+		var existing models.PurchaseGroup
+		if err := utils.DB.Where("name = ? AND id != ?", *req.Name, id).First(&existing).Error; err == nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "分组名称已存在"})
+			return
+		}
+	}
+
+	updates := make(map[string]interface{})
+	if req.Name != nil {
+		updates["name"] = *req.Name
+	}
+	if req.Description != nil {
+		updates["description"] = *req.Description
+	}
+	if req.SortOrder != nil {
+		updates["sort_order"] = *req.SortOrder
+	}
+
+	utils.DB.Model(&group).Updates(updates)
+	c.JSON(http.StatusOK, gin.H{"data": group})
+}
+
+func (h *PurchaseGroupHandler) Delete(c *gin.Context) {
+	id, _ := strconv.Atoi(c.Param("id"))
+
+	var categoryCount int64
+	utils.DB.Model(&models.Category{}).Where("purchase_group_id = ?", id).Count(&categoryCount)
+	if categoryCount > 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "该分组下有分类，无法删除"})
+		return
+	}
+
+	if err := utils.DB.Delete(&models.PurchaseGroup{}, id).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete purchase group"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "Purchase group deleted successfully"})
+}

backend/internal/api/routes/routes.go

@@ -26,6 +26,7 @@ func SetupRoutes(r *gin.Engine) {
 	paymentChannelHandler := handlers.NewPaymentChannelHandler()
 	paymentHandler := handlers.NewPaymentHandler()
 	logHandler := handlers.NewLogHandler()
+	purchaseGroupHandler := handlers.NewPurchaseGroupHandler()
 
 	r.Use(middlewares.CORSMiddleware())
 
@@ -154,6 +155,14 @@ func SetupRoutes(r *gin.Engine) {
 					adminCategories.DELETE("/:id", categoryHandler.Delete)
 				}
 
+				adminPurchaseGroups := admin.Group("/purchase-groups")
+				{
+					adminPurchaseGroups.GET("", purchaseGroupHandler.List)
+					adminPurchaseGroups.POST("", purchaseGroupHandler.Create)
+					adminPurchaseGroups.PUT("/:id", purchaseGroupHandler.Update)
+					adminPurchaseGroups.DELETE("/:id", purchaseGroupHandler.Delete)
+				}
+
 				adminBrands := admin.Group("/brands")
 				{
 					adminBrands.GET("", brandHandler.List)

backend/internal/models/category.go

@@ -7,23 +7,24 @@ import (
 )
 
 type Category struct {
-	ID                 uint           `gorm:"primaryKey" json:"id"`
-	Name               string         `gorm:"size:100;not null;uniqueIndex" json:"name"`
-	Description        string         `json:"description"`
-	ParentID           *uint          `json:"parent_id"`
-	MinAmount          *float64       `json:"min_amount"`
-	MaxAmount          *float64       `json:"max_amount"`
-	MinQuantity        *int           `json:"min_quantity"`
-	MaxQuantity        *int           `json:"max_quantity"`
-	MinWeight          *float64       `json:"min_weight"`
-	MaxWeight          *float64       `json:"max_weight"`
-	AllowCrossCategory bool           `gorm:"default:false" json:"allow_cross_category"`
-	SortOrder          int            `gorm:"default:0" json:"sort_order"`
-	CreatedAt          time.Time      `json:"created_at"`
-	UpdatedAt          time.Time      `json:"updated_at"`
-	DeletedAt          gorm.DeletedAt `gorm:"index" json:"-"`
-	ProductCount       int64          `gorm:"-" json:"product_count"`
-	Children           []Category     `gorm:"foreignKey:ParentID" json:"children,omitempty"`
+	ID               uint           `gorm:"primaryKey" json:"id"`
+	Name             string         `gorm:"size:100;not null;uniqueIndex" json:"name"`
+	Description      string         `json:"description"`
+	ParentID         *uint          `json:"parent_id"`
+	PurchaseGroupID  *uint          `json:"purchase_group_id"`
+	PurchaseGroup    *PurchaseGroup `gorm:"foreignKey:PurchaseGroupID" json:"purchase_group,omitempty"`
+	MinAmount        *float64       `json:"min_amount"`
+	MaxAmount        *float64       `json:"max_amount"`
+	MinQuantity      *int           `json:"min_quantity"`
+	MaxQuantity      *int           `json:"max_quantity"`
+	MinWeight        *float64       `json:"min_weight"`
+	MaxWeight        *float64       `json:"max_weight"`
+	SortOrder        int            `gorm:"default:0" json:"sort_order"`
+	CreatedAt        time.Time      `json:"created_at"`
+	UpdatedAt        time.Time      `json:"updated_at"`
+	DeletedAt        gorm.DeletedAt `gorm:"index" json:"-"`
+	ProductCount     int64          `gorm:"-" json:"product_count"`
+	Children         []Category     `gorm:"foreignKey:ParentID" json:"children,omitempty"`
 }
 
 func (Category) TableName() string {

backend/internal/models/purchase_group.go

@@ -0,0 +1,22 @@
+package models
+
+import (
+	"time"
+
+	"gorm.io/gorm"
+)
+
+type PurchaseGroup struct {
+	ID          uint           `gorm:"primaryKey" json:"id"`
+	Name        string         `gorm:"size:100;not null;uniqueIndex" json:"name"`
+	Description string         `json:"description"`
+	SortOrder   int            `gorm:"default:0" json:"sort_order"`
+	CreatedAt   time.Time      `json:"created_at"`
+	UpdatedAt   time.Time      `json:"updated_at"`
+	DeletedAt   gorm.DeletedAt `gorm:"index" json:"-"`
+	Categories  []Category     `gorm:"foreignKey:PurchaseGroupID" json:"categories,omitempty"`
+}
+
+func (PurchaseGroup) TableName() string {
+	return "purchase_groups"
+}

backend/internal/schemas/product.go

@@ -1,31 +1,43 @@
 package schemas
 
 type CreateCategoryRequest struct {
-	Name               string   `json:"name" binding:"required"`
-	Description        string   `json:"description"`
-	ParentID           *uint    `json:"parent_id"`
-	MinAmount          *float64 `json:"min_amount"`
-	MaxAmount          *float64 `json:"max_amount"`
-	MinQuantity        *int     `json:"min_quantity"`
-	MaxQuantity        *int     `json:"max_quantity"`
-	MinWeight          *float64 `json:"min_weight"`
-	MaxWeight          *float64 `json:"max_weight"`
-	AllowCrossCategory *bool    `json:"allow_cross_category"`
-	SortOrder          int      `json:"sort_order"`
+	Name              string   `json:"name" binding:"required"`
+	Description       string   `json:"description"`
+	ParentID          *uint    `json:"parent_id"`
+	PurchaseGroupID   *uint    `json:"purchase_group_id"`
+	MinAmount         *float64 `json:"min_amount"`
+	MaxAmount         *float64 `json:"max_amount"`
+	MinQuantity       *int     `json:"min_quantity"`
+	MaxQuantity       *int     `json:"max_quantity"`
+	MinWeight         *float64 `json:"min_weight"`
+	MaxWeight         *float64 `json:"max_weight"`
+	SortOrder         int      `json:"sort_order"`
 }
 
 type UpdateCategoryRequest struct {
-	Name               *string  `json:"name"`
-	Description        *string  `json:"description"`
-	ParentID           *uint    `json:"parent_id"`
-	MinAmount          *float64 `json:"min_amount"`
-	MaxAmount          *float64 `json:"max_amount"`
-	MinQuantity        *int     `json:"min_quantity"`
-	MaxQuantity        *int     `json:"max_quantity"`
-	MinWeight          *float64 `json:"min_weight"`
-	MaxWeight          *float64 `json:"max_weight"`
-	AllowCrossCategory *bool    `json:"allow_cross_category"`
-	SortOrder          *int     `json:"sort_order"`
+	Name            *string  `json:"name"`
+	Description     *string  `json:"description"`
+	ParentID        *uint    `json:"parent_id"`
+	PurchaseGroupID *uint    `json:"purchase_group_id"`
+	MinAmount       *float64 `json:"min_amount"`
+	MaxAmount       *float64 `json:"max_amount"`
+	MinQuantity     *int     `json:"min_quantity"`
+	MaxQuantity     *int     `json:"max_quantity"`
+	MinWeight       *float64 `json:"min_weight"`
+	MaxWeight       *float64 `json:"max_weight"`
+	SortOrder       *int     `json:"sort_order"`
+}
+
+type CreatePurchaseGroupRequest struct {
+	Name        string `json:"name" binding:"required"`
+	Description string `json:"description"`
+	SortOrder   int    `json:"sort_order"`
+}
+
+type UpdatePurchaseGroupRequest struct {
+	Name        *string `json:"name"`
+	Description *string `json:"description"`
+	SortOrder   *int    `json:"sort_order"`
 }
 
 type CreateProductRequest struct {

backend/internal/utils/database.go

@@ -63,6 +63,7 @@ func AutoMigrate() {
 	err := DB.AutoMigrate(
 		&models.User{},
 		&models.Category{},
+		&models.PurchaseGroup{},
 		&models.Brand{},
 		&models.Product{},
 		&models.ProductCustomField{},