How to solve the problem that unique setting in mongoose does not take effect

This article mainly introduces to you the solution to the problem that unique settings in mongoose database do not take effect, as well as examples of how to remove unique restrictions in Mongoose. The article introduces it in detail through sample code. Friends who need it can refer to it. I hope Can help everyone.

Preface

unique is a member of schema constraint verification. Its main function is to make the value of a certain field unique (cannot be repeated)

To maintain the uniqueness of fields, use type values: {type:String,unique:true,dropDups: true}

Note: Once mongoose modifies the data storage mechanism, the database must be restarted. Many novices have this reason when setting some properties does not take effect

The restart mentioned here is not simply closing the mongoose database server and reopening it, but first deleting the entire database and then restarting the database service

Simple schema special usage example

//导入模块

var mongoose = require('mongoose');

//连接数据库
mongoose.connect('mongodb://localhost/itheima');

//创建schema

//schema第一个参数是我们自定义的数据类型 第二个参数是管理schema默认的数据类型
var studentSchema = mongoose.Schema({
 name:{type:String,required:true},//数据类型为string，不能非空
 age:{type:Number,default:18},//数据类型为string，默认值18
 study_id:{type:Number,select:true},//学号，默认查询字段
 address:{type:String,lowercase:true},//地址，默认小写
 email:{type:String,match:RegExp(/^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+/)},//邮箱，正则表达式验证
 phone:{type:String,unique:true,dropDups: true}//电话号码唯一性
},{
  versionKey: false,//去掉版本锁 __v0

 timestamps: { createdAt: 'createTime', updatedAt: 'updateTime' }//自动管理修改时间

});

//创建model

var student = mongoose.model('student',studentSchema);

//创建Entity

var zhangsan = new student({
 name:'zhangsan',//名字必须要有，否则会报错： name: Path `name` is required.
 address:'ZhongLiang',//字符串都会变成小写
 email:'a12345@qq.com',//邮箱格式不对，添加会报错 Path `email` is invalid (a12345qq.com).
 study_id:2017001,
 phone:'123456789'//在添加唯一性字段时，mongoose会先查询数据库所有的phone值，一旦发现该值已存在则会报错
});

//添加数据



student.create(zhangsan,function(err){

 if(err){
  throw err;
 }

 console.log('插入成功' + zhangsan);

});

Mongoose removes unique restrictions

The email in the program initially set the unique restriction, resulting in emails that cannot be repeated in this collection Inserted, now want to remove the unique restriction.

db.your_collection.dropIndexes();

Related recommendations:

Two methods for mongoose to update objects

Detailed explanation of Mongoose’s virtual field query implementation method

Basic tutorial on installing and using Mongoose with Node.js to operate MongoDB_node.js

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