How to Update Multiple Attribute With Struct

Question

I was trying to make a function that can update user by given parameter.

My Method:

func UpdateMultiple(db *gorm.DB, user *User, id uint32) error {
    usr := User{}

    err := db.Debug().Model(User{}).Where("id = ?", id).Updates(map[string]interface{}{"email": user.Email, "is_active": false}).Take(&usr).Error
    if err != nil {
        return err
    }
    return nil
}

And Using like this:

Updater := &User{
    Email:    holder.Email,
    IsActive: false,
}
err = UpdateMultiple(s.DB, Updater, id)

It is working fine for now.But If want to update another field i have to change my UpdateMultiple() method. Is there any other way i can update without changing method but only changing given parameters value?

Answer 1

You can pass your User model to the Updates function, it will update all struct fields with non blank value (which means that all fields should be pointers, in order to make the best use of this feature). The code would look like this:

func UpdateMultiple(db *gorm.DB, user *User, id uint32) error {
     return db.Debug().
          Model(User{}).
          Where("id = ?", id).
          Updates(user).Error

}

See some examples from the official documentation:

// Update multiple attributes with `struct`, will only update those changed & non blank fields
db.Model(&user).Updates(User{Name: "hello", Age: 18})
//// UPDATE users SET name='hello', age=18, updated_at = '2013-11-17 21:34:10' WHERE id = 111;

// WARNING when update with struct, GORM will only update those fields that with non blank value
// For below Update, nothing will be updated as "", 0, false are blank values of their types
db.Model(&user).Updates(User{Name: "", Age: 0, Actived: false})