TLDR；如何在 buffalo 框架中在具有外键（或一般的数据库关系）的模型上创建 REST api？
我是绝对的初学者，我正在尝试使用 buffalo 框架编写一个 RESTFul 服务，遵循官方网站上给出的示例。我能够在没有数据库关系的模型上创建 RESTful api。但是当我遇到模型有外键的情况时，我被卡住了。我无法在网上找到任何文档或参考资料。我对 Go 的概念也很薄弱，您也可以在这些方面教育我。
型号：（参考：https ://gobuffalo.io/en/docs/db/relations#example
type Composer struct {
ID uuid.UUID `json:"id" db:"id"`
Name string `json:"name" db:"name"`
Description string `json:"description" db:"description"`
CreatedAt time.Time `json:"created_at" db:"created_at"`
UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
}
type Track struct {
ID uuid.UUID `json:"id" db:"id"`
Title string `json:"title" db:"title"`
Description string `json:"description" db:"description"`
Composer Composer `has_one:"composer" fk_id:"id"`
CreatedAt time.Time `json:"created_at" db:"created_at"`
UpdatedAt time.Time `json:"updated_at" db:"updated_at"`
}
资源：（参考：https ://gobuffalo.io/en/docs/resources ）
type TrackResource struct {
buffalo.Resource
}
func (v TrackResource) List(c buffalo.Context) error {
tx, ok := c.Value("tx").(*pop.Connection)
if !ok {
return errors.WithStack(errors.New("no transaction found"))
}
pieces := &models.Tracks{}
q := tx.PaginateFromParams(c.Params())
if err := q.All(pieces); err != nil {
return errors.WithStack(err)
}
c.Set("pagination", q.Paginator)
return c.Render(200, r.JSON(pieces))
}
func (v TrackResource) Show(c buffalo.Context) error {
tx, ok := c.Value("tx").(*pop.Connection)
if !ok {
return errors.WithStack(errors.New("no transaction found"))
}
piece := &models.Track{}
if err := tx.Find(piece, c.Param("track_id")); err != nil {
return c.Render(404, r.JSON(err))
}
return c.Render(200, r.JSON(piece))
}
func (v TrackResource) Create(c buffalo.Context) error {
piece := &models.Track{}
if err := c.Bind(piece); err != nil {
return errors.WithStack(err)
}
tx, ok := c.Value("tx").(*pop.Connection)
if !ok {
return errors.WithStack(errors.New("no transaction found"))
}
verrs, err := piece.Create(tx)
if err != nil {
return errors.WithStack(err)
}
if verrs.HasAny() {
return c.Render(422, r.JSON(verrs))
}
return c.Render(201, r.Auto(c, piece))
}
func (v TrackResource) Update(c buffalo.Context) error {
tx, ok := c.Value("tx").(*pop.Connection)
if !ok {
return errors.WithStack(errors.New("no transaction found"))
}
piece := &models.Track{}
if err := tx.Find(piece, c.Param("track_id")); err != nil {
return c.Error(404, err)
}
if err := c.Bind(piece); err != nil {
return errors.WithStack(err)
}
verrs, err := piece.Update(tx)
if err != nil {
return errors.WithStack(err)
}
if verrs.HasAny() {
return c.Render(422, r.JSON(verrs))
}
return c.Render(200, r.JSON(piece))
}
func (v TrackResource) Destroy(c buffalo.Context) error {
tx, ok := c.Value("tx").(*pop.Connection)
if !ok {
return errors.WithStack(errors.New("no transaction found"))
}
piece := &models.Track{}
if err := tx.Find(piece, c.Param("track_id")); err != nil {
return c.Error(404, err)
}
if err := tx.Destroy(piece); err != nil {
return errors.WithStack(err)
}
return c.Render(200, r.JSON(piece))
}
当我尝试创建轨道时。我收到错误：
json: cannot unmarshal string into Go struct field Track.Composer of type models.Composer
gitlab.com/****/****/actions.TrackResource.Create
请帮忙。