gorm golang with multiple has one

Question

I'm having trouble finding the right annotations for multiple has one which reference the same table. something like this:

type Pet struct {
    gorm.Model
    Name string
}

type PetOwner struct {
    gorm.Model
    LargestPet *Pet
    SmallestPet *Pet
    AllOthers []*Pet
}

Does anybody know what annotations and what explicit id fields would allow this to work?

Many thanks!

Answer 1

I got this working as follows:

type PetOwner struct {
    gorm.Model
    LargestPetID uint
    LargetPet *Pet `gorm:"foreignKey:LargestPetID`
    SmallestPetID uint
    SmallestPet *Pet `gorm:"foreignKey:SmallestPetID`
    AllOthers []*Pet
}

and then loading the data as follows:

var petOwner PetOwner
db.Joins("AllOthers").Joins("SmallestPet").Joins("LargestPet").Find(&petOwner)

If you want to access from the pet for which owner it is the largest pet, you can modify the pet definition as follows:

type Pet struct {
    gorm.Model
    ...
    LargestPetOf *PetOwner `gorm:"foreignKey:LargestPetID"
}

and then load this with a .Join("LargestPetOf")