如何使用自定义结构在mongo中搜索？

Question

How to ignore the default values of the time field in the query?
Because they are set in 0001-01-01 00:00:00 +0000 UTC, I can not find the right document

// User model
type User struct {
    Mail      string        `json:"mail" bson:"mail,omitempty"`
    Password  string        `json:"password" bson:"password,omitempty"`
    CreatedAt time.Time     `json:"created_at" bson:"created_at,omitempty"`
    UpdatedAt time.Time     `json:"updated_at" bson:"updated_at,omitempty"`
}

Example https://play.golang.org/p/P2P30PPtl0

Answer 1

time.Time is a struct type, and its zero value is a valid time value and is not considered "empty". So in case of time.Time if you need to differentiate between the zero and empty values, use a pointer to it instead, that is *time.Time. The nil pointer value will be the empty value, and any non-nil pointer values will denote non-empty time values.

type User struct {
    Mail      string     `json:"mail" bson:"mail,omitempty"`
    Password  string     `json:"password" bson:"password,omitempty"`
    CreatedAt *time.Time `json:"created_at" bson:"created_at,omitempty"`
    UpdatedAt *time.Time `json:"updated_at" bson:"updated_at,omitempty"`
}

See related question: Golang JSON omitempty With time.Time Field