message.model.js

@@ -4,11 +4,17 @@ const mongoose = require('mongoose');
 //ObjectId = Schema.ObjectId;
 
 const MessageSchema = mongoose.Schema({
+    //_id: ObjectId,
+    /*id: {
+        type: String,
+        getter: function(val) { return this._id.toString(); },
+        unique: true
+    },*/
+    //id: {type: String, required: true},
     subject: { type: String, required: true },
     message: { type: String, required: true },
     user: { type: String, required: true },
-    tag: [{type: String, index: true }],
-    //createtime: { type: Date, default: Date.now },
+    tag: {type: String },
 });
 
 module.exports = mongoose.model('Message', MessageSchema);