package models import "time" type UserTracker struct { UserID uint `gorm:"primaryKey;index;not null"` TrackerGUID string `gorm:"primaryKey;size:64;index;not null"` CreatedAt time.Time User User `gorm:"constraint:OnDelete:CASCADE;"` Tracker Tracker `gorm:"constraint:OnDelete:CASCADE;foreignKey:TrackerGUID;references:GUID"` }