type User struct {
    gorm.Model
    UserName    string  `json: "username" gorm: "not null; unique"`
    Email       string  `json: "email" gorm: "not null; unique"`
    FullName    string  `json: "fullName" gorm: "not null; unique"`
    Password    string  `json: "password,omitempty" gorm: "not null;type: varchar(256)"`
    ConfirmPassword string `json: "confirmPassword, omitempty" gorm: "-"`
    Picture         string `json: "picture"`
    Comments []Comment `json: "comments, omitempty"`
}