How to Update Multiple Records Using gorm? - go

Question

So I want to update movie_genre data with different genre_id values, each movie has more than 1 genre_id automatically there are multiple records in movie_genre with the same movie_id and different genre_id,
when I start trying to update with gorm by selecting only 1 genre_id, the old genre has changed, but the newly changed genre is created again in a new row with all the same column values ​​except created_at, whereas if I try to update by selecting 2 genres, the data the changed only has the value of the first genre_id, the second genre_id is not read
this is a erd database
payload json from frontend
{
"title":"Autaaa sint nihil quis ",
"release_date":"2001-01-01",
"runtime":"22",
"mpaa_rating":"G",
"rating":"4",
"description":"Eius enim distinctio1",
"id":"82",
"genre_id":["3","8"]
}:
handler
func (app *Application) UpdateMovie(ctx *gin.Context) {
var payload web.MoviePayloadResponse
if err := ctx.BindJSON(&payload); err != nil {
log.Println(err)
return
}
id, _ := strconv.Atoi(payload.ID)
movie, err := app.models.Repository.GetMovieById(id)
if err != nil {
helper.NotFound(*ctx, err)
return
}
movie.ID, _ = strconv.Atoi(payload.ID)
movie.Title = payload.Title
movie.Description = payload.Description
movie.ReleaseDate, _ = time.Parse("2006-01-02", payload.ReleaseDate)
movie.Year = movie.ReleaseDate.Year()
movie.Runtime, _ = strconv.Atoi(payload.Runtime)
movie.Rating, _ = strconv.Atoi(payload.Rating)
movie.MPAARating = payload.MPAARating
movie.UpdatedAt = time.Now()
err = app.models.Repository.UpdateMovie(movie, id)
if err != nil {
panic(err)
}
movieGenre, _ := app.models.Repository.GetMovieGenresById(id)
for _, mg := range *movieGenre {
mg.MovieID = movie.ID
mg.UpdatedAt = time.Now()
for _, v := range payload.GenreID {
mg.GenreID, _ = strconv.Atoi(v)
err := app.models.Repository.UpdateMovieGenre(&mg, id)
if err != nil {
panic(err)
}
}
}
ctx.JSON(http.StatusOK, &gin.H{
"ok": "response",
})
return
}
repository
func (MovieRepositoryImpl *MovieRepositoryImpl) UpdateMovie(movie *Movie, id int) error {
err := MovieRepositoryImpl.DB.Where("id = ?", id).Save(&movie).Error
if err != nil {
return err
}
return nil
}
func (MovieRepositoryImpl *MovieRepositoryImpl) UpdateMovieGenre(movieGenre *MovieGenre, id int) error {
err := MovieRepositoryImpl.DB.Where("movie_id = ?", id).Save(&movieGenre).Error
if err != nil {
return err
}
return nil
}
func (MovieRepositoryImpl *MovieRepositoryImpl) GetMovieGenresById(id int) (*[]MovieGenre, error) {
var movie []MovieGenre
err := MovieRepositoryImpl.DB.Where("movie_id = ?", id).Find(&movie).Error
if err != nil {
return nil, err
}
return &movie, nil
}
Model
type Movie struct {
ID int `json:"id"`
Title string `json:"title"`
Description string `json:"description"`
Year int `json:"year"`
ReleaseDate time.Time `json:"release_date"`
Runtime int `json:"runtime"`
Rating int `json:"rating"`
MPAARating string `json:"mpaa_rating"`
CreatedAt time.Time `json:"created_at"`
UpdatedAt time.Time `json:"updated_at"`
Genres []Genre `json:"genres" gorm:"many2many:movie_genres"`
MovieGenre []MovieGenre `json:"movie_genres" gorm:"many2many:movie_genres"`
}
type Genre struct {
ID int `json:"id"`
GenreName string `json:"name"`
Movies []Movie `json:"movies" gorm:"many2many:movie_genres"`
CreatedAt time.Time `json:"-"`
UpdatedAt time.Time `json:"-"`
}
type MovieGenre struct {
ID int `json:"id"`
MovieID int `json:"movie_id"`
Movie Movie `gorm:"foreignKey:MovieID"`
GenreID int `json:"genre_id"`
Genre Genre `gorm:"foreignKey:GenreID"`
CreatedAt time.Time `json:"-"`
UpdatedAt time.Time `json:"-"`
}
type MoviePayloadResponse struct {
ID string `json:"id"`
Title string `json:"title"`
Description string `json:"description"`
Year string `json:"year"`
ReleaseDate string `json:"release_date"`
Runtime string `json:"runtime"`
Rating string `json:"rating"`
MPAARating string `json:"mpaa_rating"`
GenreID []string `json:"genre_id"`
CreatedAt string `json:"created_at"`
UpdatedAt string `json:"updated_at"`
}
My expectation is that the data genre_id that changes is only data whose value is not the same as the value in the payload, if it is the same then the data does not change, if it is different then it changes, and if the data in the payload exceeds the original genre data, then new data is automatically created. That's roughly what it looks like. Please help!!