Automatically update fields

Qmgo support two ways to make specific fields automatically update in specific API, check examples here:

Default fields

• Inject field.DefaultField in document struct, Qmgo will update createAt、updateAt and _id in update and insert operation.

type User struct {
    field.DefaultField `bson:",inline"`
    Name string `bson:"name"`
    Age  int    `bson:"age"`
}
u := &User{Name: "Lucas", Age: 7}
_, err := cli.InsertOne(context.Background(), u)
// Fields with tag createAt、updateAt and _id will be generated automatically 

• Support fields:

Field	Supported type	Supported API
CreateAt	time.Time	InsertOne / InsertMany / Upsert / UpdateId / UpsertId
UpdateAt	time.Time	InsertOne / InsertMany / Upsert / ReplaceOne / UpdateId / UpsertId
Id	primitive.ObjectID	InsertOne / InsertMany / Upsert / UpdateId / UpsertId

Note:To Field Id and API Upsert,if replacement document in Upsert has "_id" field and the document exists, please initial it with existing id.

Custom fields

• The document *struct has to implement:

CustomFields() field.CustomFieldsBuilder

• Define the custom fields, Qmgo will update them in update and insert operation.

type User struct {
    Name string `bson:"name"`
    Age  int    `bson:"age"`

    MyId         string    `bson:"myId"`
    CreateTimeAt time.Time `bson:"createTimeAt"`
    UpdateTimeAt int64     `bson:"updateTimeAt"`
}

// Implement CustomFields() field.CustomFieldsBuilder 
// And define the custom fields
func (u *User) CustomFields() field.CustomFieldsBuilder {
    return field.NewCustom().SetCreateAt("CreateTimeAt").SetUpdateAt("UpdateTimeAt").SetId("MyId")
}

u := &User{Name: "Lucas", Age: 7}
_, err := cli.InsertOne(context.Background(), u)
// CreateTimeAt、UpdateTimeAt and MyId will be generated automatically 
  
// suppose Id and ui is ready
err = cli.ReplaceOne(context.Background(), bson.M{"_id": Id}, &ui)
// UpdateTimeAt will update

• Supported fields

Field	Supported type	Supported API
Custom createAt filed	time.Time / int64(unix timestamp)	InsertOne / InsertMany / Upsert / UpdateId / UpsertId
Custom updateAt field	time.Time / int64(unix timestamp)	InsertOne / InsertMany / Upsert / ReplaceOne
Custom Id field	primitive.ObjectID/string	InsertOne / InsertMany / Upsert / UpdateId / UpsertId

note:To Field Custom Id and API Upsert,if replacement document in Upsert has "_id" field and the document exists, please initial it with existing id.