mongoose查询时排除过滤某个字段的两种方法

以过滤掉password字段为例
1. password:0

User.findOne({username, password: md5(password)}, {password:0}, function (err, user)
{
 //处理逻辑
})

2. select:false
直接在定义schema规则的时候就规定查询的时候不返回password

var userSchema = new mongoose.Schema({
  username: {
    type:String,
    required:true,
    minlength:2,
    maxlength:20
  },
  password: {
    type:String,
    required:true,
    select:false
  },
})