我为一个用户实体创建了一个Mongoose数据库模式,并希望在updated_at
字段中添加当前日期.我试图使用.pre('save', function() {})
回调,但每次运行它时,我都会收到一条错误消息,告诉我this
未定义.我还决定使用ES6,我想这可能是一个原因(尽管一切都正常).我的mongoose / node ES6代码如下:
import mongoose from 'mongoose'
mongoose.connect("mongodb://localhost:27017/database", (err, res) => {
if (err) {
console.log("ERROR: " + err)
} else {
console.log("Connected to Mongo successfuly")
}
})
const userSchema = new mongoose.Schema({
"email": { type: String, required: true, unique: true, trim: true },
"username": { type: String, required: true, unique: true },
"name": {
"first": String,
"last": String
},
"password": { type: String, required: true },
"created_at": { type: Date, default: Date.now },
"updated_at": Date
})
userSchema.pre("save", (next) => {
const currentDate = new Date
this.updated_at = currentDate.now
next()
})
const user = mongoose.model("users", userSchema)
export default user
错误消息是:
undefined.updated_at = currentDate.now;
^
TypeError: Cannot set property 'updated_at' of undefined
编辑:通过使用@vbranden的答案并将其从词法函数更改为标准函数,修复了此问题.然而,我后来遇到了一个问题,虽然它不再显示错误,但它没有更新对象中的updated_at
字段.我把this.updated_at = currentDate.now
改成了this.updated_at = currentDate
.