使用GORM进行Golang的一对一关系映射

我试图了解GORM如何与MySQL进行一对一的关系映射 . 我有两个这样的结构：

type User struct {
    Id              uint   `gorm:"AUTO_INCREMENT"`
    FirstName       string `gorm:"column:first_name"`
    LastName        string `gorm:"column:last_name"`
    EncryptedUserId string `gorm:"size:255"`
    Email           string `gorm:"not null;unique"`
    Password        string `gorm:"not null;unique"`
    CreatedAt       int64  `gorm:"type(timestamp)"`
}

type UserSession struct {
    Id           uint `gorm:"AUTO_INCREMENT"`
    UserId       User 
    SessionToken string `gorm:"column:session_token"`
    CreatedAt    int64  `gorm:"type(timestamp)"`
}

UserUserSessionUserSessionUserIdgorm:"ForeignKey:Id"