在mgo中定义MongoDB模式/集合

Question

I want to use mgo to create/save a MongoDB collection. But I would like to define it more extensively (for e.g to mention that one of the attribute is mandatory, another one is of an enum type and has a default value).

I have defined the struct like this, but don't know how to describe the constraints on it.

type Company struct {
    Name        string `json:"name" bson:"name"` // --> I WANT THIS TO BE MANDATORY
    CompanyType string `json:"companyType" bson:"companyType"` // -->I WANT THIS TO BE AN ENUM
}

Is this possible to do in mgo, like how we can do it in MongooseJS?

Answer 1

mgo isn't an ORM or a validation tool. mgo is only an interface to MongoDB.

It's not bad to do validation all by yourself.

type CompanyType int

const (
  CompanyA CompanyType = iota // this is the default
  CompanyB CompanyType
  CompanyC CompanyType
)

type Company struct {
  Name string
  CompanyType string
}

func (c Company) Valid() bool {
  if c.Name == "" {
    return false
  }
  // If it's a user input, you'd want to validate CompanyType's underlying
  // integer isn't out of the enum's range.
  if c.CompanyType < CompanyA || c.CompanyType > CompanyB {
    return false
  }
  return true
}

Check this out for more about enums in Go.