diff --git a/src/moogoose/demo.js b/src/moogoose/demo.js
new file mode 100644
index 0000000..5dc6bc5
--- /dev/null
+++ b/src/moogoose/demo.js
@@ -0,0 +1,68 @@
+// models/DiaryEntry.js
+const mongoose = require('mongoose');
+
+const DiaryEntrySchema = new mongoose.Schema({
+  userId: {
+    type: mongoose.Schema.Types.ObjectId,
+    ref: 'User', // 关联用户（支持多用户）
+    required: true
+  },
+  title: {
+    type: String,
+    trim: true,
+    default: '无标题'
+  },
+  content: {
+    type: String,
+    required: true,
+    trim: true
+  },
+  date: {
+    type: Date,
+    default: Date.now,
+    index: true // 为日期建立索引，加速按日查询
+  },
+  tags: [{
+    type: String,
+    lowercase: true,
+    trim: true
+  }],
+  mood: {
+    type: Number,
+    min: 1,
+    max: 5,
+    default: 3, // 1=非常差，5=非常好
+    index: true
+  },
+  weather: {
+    type: String,
+    enum: ['晴', '阴', '雨', '雪', '雾', '其他'],
+    default: '其他'
+  },
+  location: {
+    lat: Number,
+    lng: Number,
+    address: String
+  },
+  media: [{
+    type: String, // 图片/音频/视频 URL
+    trim: true
+  }],
+  createdAt: {
+    type: Date,
+    default: Date.now
+  },
+  updatedAt: {
+    type: Date,
+    default: Date.now
+  }
+}, {
+  timestamps: true // 自动管理 createdAt / updatedAt
+});
+
+// 为常用查询建立复合索引
+DiaryEntrySchema.index({ userId: 1, date: -1 }); // 按用户+日期降序（最新在前）
+DiaryEntrySchema.index({ userId: 1, tags: 1 });  // 按标签查找
+DiaryEntrySchema.index({ userId: 1, mood: 1 });  // 按情绪筛选
+
+module.exports = mongoose.model('DiaryEntry', DiaryEntrySchema);
\ No newline at end of file