Initial commit: 宁夏智慧养殖监管平台

backend/models/OrderItem.js

@@ -0,0 +1,140 @@
+/**
+ * OrderItem 模型定义
+ * @file OrderItem.js
+ * @description 定义订单项模型，用于数据库操作
+ */
+const { DataTypes } = require('sequelize');
+const BaseModel = require('./BaseModel');
+const { sequelize } = require('../config/database-simple');
+
+/**
+ * 订单项模型
+ * @typedef {Object} OrderItem
+ * @property {number} id - 订单项唯一标识
+ * @property {number} order_id - 订单ID
+ * @property {number} product_id - 产品ID
+ * @property {number} quantity - 数量
+ * @property {number} price - 单价（单位：分）
+ * @property {Date} created_at - 创建时间
+ */
+class OrderItem extends BaseModel {
+  /**
+   * 获取订单的所有订单项
+   * @param {Number} orderId 订单ID
+   * @returns {Promise<Array>} 订单项列表
+   */
+  static async getOrderItems(orderId) {
+    return await this.findAll({
+      where: { order_id: orderId },
+      include: [{ model: sequelize.models.Product }]
+    });
+  }
+
+  /**
+   * 计算订单项总金额
+   * @returns {Number} 总金额
+   */
+  getTotalPrice() {
+    return this.price * this.quantity;
+  }
+
+  /**
+   * 更新订单项数量
+   * @param {Number} quantity 新数量
+   * @returns {Promise<Boolean>} 更新结果
+   */
+  async updateQuantity(quantity) {
+    try {
+      if (quantity <= 0) {
+        throw new Error('数量必须大于0');
+      }
+      
+      // 检查产品库存
+      const product = await sequelize.models.Product.findByPk(this.product_id);
+      
+      if (!product) {
+        throw new Error('产品不存在');
+      }
+      
+      const quantityDiff = quantity - this.quantity;
+      
+      if (quantityDiff > 0 && !product.hasEnoughStock(quantityDiff)) {
+        throw new Error('产品库存不足');
+      }
+      
+      // 使用事务确保数据一致性
+      const result = await sequelize.transaction(async (t) => {
+        // 更新订单项数量
+        this.quantity = quantity;
+        await this.save({ transaction: t });
+        
+        // 更新产品库存
+        await product.updateStock(-quantityDiff, { transaction: t });
+        
+        // 更新订单总金额
+        const order = await sequelize.models.Order.findByPk(this.order_id, { transaction: t });
+        await order.calculateTotal({ transaction: t });
+        
+        return true;
+      });
+      
+      return result;
+    } catch (error) {
+      console.error('更新订单项数量失败:', error);
+      return false;
+    }
+  }
+}
+
+// 初始化OrderItem模型
+OrderItem.init({
+  id: {
+    type: DataTypes.INTEGER,
+    primaryKey: true,
+    autoIncrement: true
+  },
+  order_id: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+    references: {
+      model: 'orders',
+      key: 'id'
+    },
+    onDelete: 'CASCADE'
+  },
+  product_id: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+    references: {
+      model: 'products',
+      key: 'id'
+    },
+    onDelete: 'RESTRICT'
+  },
+  quantity: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+    defaultValue: 1,
+    validate: {
+      min: 1
+    }
+  },
+  price: {
+    type: DataTypes.INTEGER,
+    allowNull: false,
+    comment: '单位：分'
+  }
+}, {
+  sequelize,
+  tableName: 'order_items',
+  modelName: 'OrderItem',
+  timestamps: true,
+  createdAt: 'created_at',
+  updatedAt: false
+});
+
+/**
+ * 导出订单项模型
+ * @exports OrderItem
+ */
+module.exports = OrderItem;