Example.go

type User struct {
	ID            int64       `gorm:"primary_key;auto_increment" json:"id"`
	NickName      string      `gorm:"size:255;not null;unique" db:"nick_name" json:"nickName"`
	Avatar        string      `gorm:"size:255;unique" db:"avatar" json:"avatar"`
	Name          string      `gorm:"size:255;not null" json:"name"`
	LastName      string      `gorm:"size:255;not null" db:"last_name" json:"lastName"`
	Phone         string      `gorm:"size:16;not null;unique" json:"phone"`
	RememberToken string      `gorm:"size:255;not null" db:"remember_token" json:"rememberToken"`
	Email         string      `gorm:"size:100;not null;unique" json:"email"`
	Password      string      `gorm:"size:100;not null;" json:"password"`
	Active        bool        `gorm:"DEFAULT:true" json:"active" db:"active" `
	NotifyToken   NotifyToken `json:"notifyToken" db:"notify_token"`
	Friends       []Friends   `json:"friends" db:"friends"`
	LoginAt       time.Time   `gorm:"default:CURRENT_TIMESTAMP" json:"loginAt"`
	CreatedAt     time.Time   `gorm:"default:CURRENT_TIMESTAMP" json:"createdAt"`
	UpdatedAt     time.Time   `gorm:"default:CURRENT_TIMESTAMP" json:"updatedAt"`
}


type Friends struct {
	ID int64 `json:"id" gorm:"primary_key:true"`
	OwnerID   int64        `json:"ownerId"  `
	FriendID  int64        `json:"friendId" `
	Blocked   bool         `json:"blocked"`
	BlockedAt sql.NullTime `gorm:"default:null" json:"blockedAt"`
	CreatedAt time.Time    `gorm:"default:CURRENT_TIMESTAMP" json:"createdAt"`
}

//gorm ile yaptığım sorgum

func (u *User) FindUsersBySearch(db *gorm.DB, search string, myID int64) (*[]User, error) {
	var err error
	users := []User{}
	// search = fmt.Sprintf("%"+"%s%", search)
	fmt.Println("search", search)
	db.Debug().LogMode(true).Preload("Friends").Model(users).Table("users").Select("*").Joins("inner join friends on friends.owner_id=users.id or friends.friend_id=users.id").Where("public.users.name LIKE ? OR users.nick_name LIKE ? OR users.last_name LIKE ?", "%"+search+"%", "%"+search+"%", "%"+search+"%").Not("id", myID).Find(&users)
	err = db.Error

	if err != nil {
		return &[]User{}, err
	}
	if gorm.IsRecordNotFoundError(err) {
		return &[]User{}, errors.New("Users Not Found")
	}
	for _, ar := range users {
		fmt.Println("users", ar.Friends)

	}

	return &users, err
}

https://jinzhu.me/gorm/associations.html
Burdaki gibi Foreign Key ve Association Key belirtmelisin.