mongoose数据校验是指用户通过mongoose给mongodb数据库增加数据的时候，对数据的合法性进行的验证，在mongoose里面定义Schema的时候，通过设置字段类型，修饰符、默认参数 、数据校验等都是为了数据库数据的一致性。
​​​required​​​: 表示这个数据必须传入
​​​max​​​: 用于 Number 类型数据，最大值
​​​min​​​: 用于 Number 类型数据，最小值
​​​enum​​​:枚举类型，用于String要求数据必须满足枚举值 enum: ['0', '1', '2']
​​​match​​​:增加的数据必须符合 match（正则）的规则
​​​maxlength​​​：最大值
​​​minlength​​：最小值

var mongoose=require('./db.js');
var UserSchema=mongoose.Schema({
    name:{
        type:String,//指定类型
        trim:true,   //修饰符         
        required:true //该数据不能缺省
    },
    sn:{
        type:String,
        index:true,  //普通索引.
        set(val){  //自定义修饰符
            return val;
        },
        // maxlength:20,//长度不能超过20
        // minlength:10//长度不能小于10
        // match:/^sn(.*)/ ,//必须符合该正则表达式
        validate: function(sn) {//自定义验证规则
            return sn.length >= 10;
        }
　　　　// 也可以是
validator: function(v) {
        　　return /\d{3}-\d{3}-\d{4}/.test(v);
      　　},
      　　message: props => `${props.value} is not a valid phone number!`
    　　},
},   
    age:{
        type:Number,
        min:0,    //用在number类型上面
        max:150//最大值为150
    },       
    status:{
        type:String, 
        default:'success', //默认值
        enum:['success','error']   //status的值必须在 对应的数组里面  注意枚举是用在String
    }
})
module.exports=mongoose.model('User',UserSchema,'user');
const breakfastSchema = new Schema({
  eggs: {
    type: Number,

    min: [6, 'Must be at least 6, got {VALUE}'], // 可以传一个数组 {VALUE}会被替换为校验的值
    max: 12
  },
  drink: {
    type: String,
    enum: {
      values: ['Coffee', 'Tea'],
      message: '{VALUE} is not supported'
    }
  }
});
const Breakfast = db.model('Breakfast', breakfastSchema);

const badBreakfast = new Breakfast({
  eggs: 2,
  drink: 'Milk'
});
let error = badBreakfast.validateSync();
assert.equal(error.errors['eggs'].message,
  'Must be at least 6, got 2');
assert.equal(error.errors['drink'].message, 'Milk is not supported');

 

const breakfastSchema = new Schema({
  eggs: {
    type: Number,
    min: [6, 'Too few eggs'],
    max: 12
  },
  bacon: {
    type: Number,
    required: [true, 'Why no bacon?']
  },
  drink: {
    type: String,
    enum: ['Coffee', 'Tea'],
    required: function() { // 也可以是自定义的函数
      return this.bacon > 3;
    }
  }
});
const Breakfast = db.model('Breakfast', breakfastSchema);

const badBreakfast = new Breakfast({
  eggs: 2,
  bacon: 0,
  drink: 'Milk'
});
let error = badBreakfast.validateSync();
assert.equal(error.errors['eggs'].message,
  'Too few eggs');
assert.ok(!error.errors['bacon']);
assert.equal(error.errors['drink'].message,
  '`Milk` is not a valid enum value for path `drink`.');

badBreakfast.bacon = 5;
badBreakfast.drink = null;

error = badBreakfast.validateSync();
assert.equal(error.errors['drink'].message, 'Path `drink` is required.');

badBreakfast.bacon = null;
error = badBreakfast.validateSync();
assert.equal(error.errors['bacon'].message, 'Why no bacon?');