我正在尝试将产品插入到具有关联类别的数据库中。一种产品可以属于几个类别,显然一个类别可以有几种产品。当我插入时,我确信我在控制器方法中遗漏了一些东西,但我不确定它是什么。我有一个名为ProductCategory的桥表,其中只有一个ProductID和一个CategoryID。当我插入时,该表格没有填充。
这是我执行插入的控制器方法:
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult EditProduct([Bind(Include = "ID,itemNumber,product,description,active,PDFName,imageName,SelectedCategories")] ProductModel model)
{
if (ModelState.IsValid)
{
using (var context = new ProductContext())
{
context.Database.Log = s => System.Diagnostics.Debug.WriteLine(s);
if (model.ID == 0)
{
// Since it didn't have a ProductID, we assume this
// is a new Product
if (model.description == null || model.description.Trim() == "")
{
model.description = "Our Famous " + model.product;
}
if (model.imageName == null || model.imageName.Trim() == "")
{
model.imageName = model.itemNumber + ".jpg";
}
if (model.PDFName == null || model.PDFName.Trim() == "")
{
model.PDFName = model.itemNumber + ".pdf";
}
Session["dropdownID"] = model.ID;
// I think I probably need some additional code here...
context.Products.Add(model);
}
else
{
// Since EF doesn't know about this product (it was instantiated by
// the ModelBinder and not EF itself, we need to tell EF that the
// object exists and that it is a modified copy of an existing row
context.Entry(model).State = EntityState.Modified;
}
context.SaveChanges();
return RedirectToAction("ControlPanel");
}
}
return View(model);
}
我的产品型号:
public class ProductModel
{
public int ID { get; set; }
[Required(ErrorMessage = "Required")]
[Index("ItemNumber", 1, IsUnique = true)]
[Display(Name = "Item #")]
public int itemNumber { get; set; }
[Required(ErrorMessage = "Required")]
[Display(Name = "Product")]
[MaxLength(50)]
public String product { get; set; }
[Display(Name = "Description")]
[MaxLength(500)]
public String description { get; set; }
[DefaultValue(true)]
[Display(Name = "Active?")]
public bool active { get; set; }
[Display(Name = "Image Name")]
public String imageName { get; set; }
[Display(Name = "PDF Name")]
public String PDFName { get; set; }
[Display(Name = "Category(s)")]
public virtual ICollection<CategoryModel> ProductCategories { get; set; }
public int[] SelectedCategories { get; set; }
public IEnumerable<SelectListItem> CategorySelectList { get; set; }
//public ICollection<CategoryModel> CategoryList { get; set; }
public virtual BrochureModel Brochure { get; set; }
public IEnumerable<SelectListItem> BrochureList { get; set; }
[Display(Name = "Category(s)")]
public String CategoryList { get; set; }
public static IEnumerable<SelectListItem> getCategories(int id = 0)
{
using (var db = new ProductContext())
{
List<SelectListItem> list = new List<SelectListItem>();
var categories = db.Categories.ToList();
foreach (var cat in categories)
{
SelectListItem sli = new SelectListItem { Value = cat.ID.ToString(), Text = cat.categoryName };
//if (id > 0 && cat.ID == id)
//{
// sli.Selected = true;
//}
list.Add(sli);
}
return list;
}
}
public ProductModel()
{
active = true;
}
}
我的分类型号:
public class CategoryModel
{
public int ID { get; set; }
[Required(ErrorMessage = "Required")]
[Display(Name = "Category Name")]
[MaxLength(50)]
public String categoryName { get; set; }
[MaxLength(50)]
public String categoryDBName { get; set; }
[DefaultValue(true)]
[Display(Name = "Active?")]
public bool isActive { get; set; }
//public virtual ICollection<ProductCategory> ProductCategories { get; set; }
public virtual ICollection<ProductModel> Products { get; set; }
}
这是我的产品背景:
public class ProductContext : DbContext
{
public ProductContext()
: base("DefaultConnection")
{
Database.SetInitializer<ProductContext>(new CreateDatabaseIfNotExists<ProductContext>());
}
public DbSet<CategoryModel> Categories { get; set; }
public DbSet<ProductModel> Products { get; set; }
public DbSet<BrochureModel> Brochures { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
//modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
//modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
modelBuilder.Entity<CategoryModel>().ToTable("Categories");
modelBuilder.Entity<ProductModel>().ToTable("Products");
modelBuilder.Entity<BrochureModel>().ToTable("Brochures");
modelBuilder.Entity<ProductModel>()
.HasMany(p => p.ProductCategories)
.WithMany(p => p.Products)
.Map(m =>
{
m.ToTable("ProductCategory");
m.MapLeftKey("ProductID");
m.MapRightKey("CategoryID");
});
//modelBuilder.Entity<CategoryModel>()
//.HasMany(c => c.ProductCategories)
//.WithRequired()
//.HasForeignKey(c => c.CategoryID);
}
public System.Data.Entity.DbSet<newBestPlay.Models.RegisterViewModel> RegisterViewModels { get; set; }
}
如果需要其他代码或更多信息,请告诉我。
答案 0 :(得分:1)
你永远不会对你的SelectedCategories
数组做任何事情。您需要使用它从数据库中提取CategoryModel
实例,然后将其与产品相关联。
context.Categories.Where(c => model.SelectedCategories.Contains(c.ID)).ToList()
.ForEach(c => model.ProductCategories.Add(c));
...
context.SaveChanges();
<强>更新强>
我可以询问如何在我的视图中列出每种产品的类别吗?
这是一个有问题的问题,因为它高度依赖于你想要实现的体验类型。一般来说,对于任何集合,您需要迭代该集合中的项目,然后为每个项目呈现一些HTML。你可以通过多种不同的方式做到这一点,这就是为什么我不能给你一个“正确”的答案。但是,只是为了给你一个想法,而不是让你没有任何代码,这里是一个非常基本的方法来列出每个类别的名称:
@string.Join(", ", Model.ProductCategories.Select(c => c.categoryName))