Turn two gorm queries into one

I have the following models

type Instance struct {
	gorm.Model
	Name               string `gorm:"index:idx_name_and_group,unique"`
	UserID             uint
	GroupID            uint `gorm:"index:idx_name_and_group,unique"`
    ...
}

type Group struct {
	gorm.Model
	Name                 string `gorm:"unique;"`
	Instances            []Instance
    ...
}

I'm trying to get an instance by name and group name.

I can do it using the following code

func (r instanceRepository) FindByName(groupName string, instanceName string) (*model.Instance, error) {
	var instance *model.Instance
	var group *model.Group

	err := r.db.
		First(&group, "name = ?", groupName).Error
	if err != nil {
		return nil, err
	}

	err = r.db.
		Where("name = ? and group_id = ?", instanceName, group.ID).
		First(&instance).Error

	return instance, err
}

But I'd like to turn it into one query. Any ideas about how to achieve that?

You can always use the Joins function to do SQL joins. Something like this:

func (r instanceRepository) FindByName(groupName string, instanceName string) (*model.Instance, error) {
    var instance *model.Instance

    err := r.db.
        Joins("INNER JOIN groups g ON g.id = instances.group_id").
        Where("g.name = ? AND instances.name = ?", groupName, instanceName).
        First(&instance).Error
    if err != nil {
        return nil, err
    }

    return instance, err
}