Entity framework insert error - entity-framework

I have 3 class table
and Category table have 1 record ,for example catID = 2 ...
and There is no record of the product table
now , When adding a new record to the table Images ,
When I entered CategpryID = 2 , ProductID = 0 ...
I am getting error :(
What do I need ???*
[Table("Products")]
public class Product
{
public Product()
{
Images = new List<Image>();
}
public int ProductID { get; set; }
public string Name { get; set; }
public List<Image> Images { get; set; }
}
[Table("Categorys")]
public class Category
{
public Category()
{
Images = new List<Image>();
}
public int CategpryID { get; set; }
public string Name { get; set; }
public List<Image> Images { get; set; }
}
[Table("Images")]
public class Image
{
[Key]
public int ImageID { get; set; }
public int CategpryID { get; set; }
public int ProductID { get; set; }
public string ImageURL { get; set; }
public Product Product { get; set; }
public Category Category { get; set; }
}

Related

trying to make an ecommerce website in asp.net mvc5

I am trying to make an ecommerce website using entity framework code first but am having a problem with the basket I don't need add bank accounts or any kind the payment method is pay on delivery I got the Icon ready as a button
<dd>
#Html.ActionLink("Add","Basket",new { id = this.Model.Id },new { #class = "btn btn-primary"})
</dd>
once clicked it will activate the action method
public ActionResult Basket(int Id)
{
PB.basket(Id);
return View();
}
witch will activate a method called basket
public void basket(int Id)
{
List<Basket> bst = new List<Basket>();
var user = HttpContext.Current.Session.SessionID;
var prd = db.Products.Where(p => p.Id == Id).FirstOrDefault();
bst.Add(new Basket()
{
Price = prd.Price,
ProductId = prd.Id,
Count = 1,
}) ;
}
here are the classes witch the database for it is created
using identity
public class users
{
public string Id { get; set; }
public string UserName { get; set; }
public string Email { get; set; }
public string Address { get; set; }
public string PhoneNumber { get; set; }
}
public class Product
{
public int Id { get; set; }
[Display(Name = "Product Name")]
public string ProductName { get; set; }
[DataType(DataType.ImageUrl)]
public string Image { get; set; }
public string Category { get; set; }
public double Price { get; set; }
[DataType(DataType.Text)]
public string Description { get; set; }
[NotMapped]
public HttpPostedFileBase ImageFile { get; set; }
}
public class Basket
{
public int Id { get; set; }
public int ProductId { get; set; }
public int Count { get; set; }
public double Price { get; set; }
public ApplicationUser user { get; set; }
public Product Product { get; set; }
public ICollection<Product> products { get; set; }
public ICollection<ApplicationUser> users { get; set; }
}
please help

Using Automapper through a join table in EFCore

I have a many-to-many relationship between Recipe and Item via a join table called Ingredient:
public class Recipe
{
public int RecipeId { get; set; }
public string Name { get; set; }
public ICollection<RecipeInstruction> RecipeInstructions { get; set; }
public ICollection<Ingredient> Ingredients { get; set; }
}
public class Ingredient
{
public Recipe Recipe { get; set; }
public int RecipeId { get; set; }
public Item Item { get; set; }
public int ItemId { get; set; }
public int Quantity { get; set; }
}
public class Item
{
public int ItemId { get; set; }
public string Name { get; set; }
public string Brand { get; set; }
public ICollection<Ingredient> Ingredients { get; set; }
}
I would like to present the data through this DTO:
public class RecipeForDetailedDto
{
public int RecipeId { get; set; }
public string Name { get; set; }
public ICollection<RecipeInstruction> RecipeInstructions { get; set; }
public ICollection<ItemForDetailedDto> Ingredients { get; set; }
}
Is there a way I can map this relationship to show a list of Ingredient names, which would be the Item Name?
It should look like this:
CreateMap<Ingredient, ItemForDetailedDto>();
CreateMap<Ingredient,RecipeForDetailedDto>()
.ForMember(dest=>dest.Name, opt=>opt.MapFrom(src=>src.Item?.Name));
var result = mapper.Map<ItemDetailedDto>(yourIngredientObject);
In the end this is what worked:
CreateMap<Ingredient, IngredientForDetailedDto>()
.ForMember(dest => dest.Name, opt => opt.MapFrom(src => src.Item.Name))
With IngredientForDetailedDto as:
public class IngredientForDetailedDto
{
public string Name { get; set; }
public int Quantity { get; set; }
public string QuantityType { get; set; }
}

Method based linq queries

I have five tables in database whose Entity classes are as follows -
Product
public int ProductId { get; set; }
public string Name { get; set; }
public int Category { get; set; }
public string Description { get; set; }
public string Brand { get; set; }
public virtual ProductCategory ProductCategory { get; set; }
public virtual ICollection<ProductImage> ProductImages { get; set; }
public virtual ICollection<ProductVariantMapping> ProductVariantMappings
ProductCategory
public int CategoryId { get; set; }
public string Name { get; set; }
public virtual ICollection<Product> Products { get; set; }
ProductImage
public int ProductImageId { get; set; }
public int ProductId { get; set; }
public byte[] Image { get; set; }
public virtual Product Product { get; set; }
ProductVariantMapping
public int MappingId { get; set; }
public int ProductId { get; set; }
public int ProductVariantId { get; set; }
public string Value { get; set; }
public System.Guid GUID { get; set; }
public virtual Product Product { get; set; }
public virtual ProductVariant ProductVariant { get; set; }
ProductVariant
public int ProductVariantId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public virtual ICollection<ProductVariantMapping> ProductVariantMappings
I want to get Product Details which should include ProductId, ProductName, Category, Description, Brand, Image(Only 1 for now), and Variants*
*Variants would be a list of all the variants of a product. A single variant can be a combination of all the VariantIds with same GUIDs. (VariantName is in ProductVariant table and VariantValue is in ProductVariantMapping table and Price is in inventory table).
So, I used method-based linq for this purpose.
EkartEntities ekartEntities = new EkartEntities();
var productDetails = ekartEntities.Products.Include(p =>
p.ProductVariantMappings).Include(p => p.ProductImages).Include(p =>
p.ProductCategory).Where(p => p.ProductId ==
productDetailDTO.ProductId).ToList();
Now I have to convert my product into a ProductDetailDTO.
ProductDetailDTO
public class ProductDetailDTO
{
public int ProductId { get; set; }
public string Name { get; set; }
public string Category { get; set; }
public byte[] Image { get; set; }
public string Description { get; set; }
public string Brand { get; set; }
public List<Variant> Variants { get; set; }
}
public class Variant
{
public string Name { get; set; }
public string Value { get; set; }
public System.Guid Guid { get; set; }
public decimal Price { get; set; }
}
I started doing this like this -
void ToDTO(List<Product> products)
{
EkartEntities ekartEntities = new EkartEntities();
ProductDetailDTO productDetailDTO = new ProductDetailDTO();
foreach (var item in products)
{
productDetailDTO.ProductId = item.ProductId;
productDetailDTO.Name = item.Name;
productDetailDTO.Category = item.ProductCategory.Name;
productDetailDTO.Description = item.Description;
productDetailDTO.Brand = item.Brand;
productDetailDTO.Image = item.ProductImages.ElementAt(0).Image;
foreach (var variant in item.ProductVariantMappings)
{
productDetailDTO.Variants = variant.ProductVariant // ?
}
}
}
I don't know how do I proceed further. How can I extract the variant based on the GUIDs?
The logic of combining of ProductVariant entries with same GUID in mapping table doesn't seem clear from the question, however you can group entries in ProductVariantMappings by GUID and then add any logc you like on group. Here is an example where I take first name and value in a groub of variant with the same GUID:
void ToDTO(List<Product> products)
{
EkartEntities ekartEntities = new EkartEntities();
ProductDetailDTO productDetailDTO = new ProductDetailDTO();
foreach (var item in products)
{
productDetailDTO.ProductId = item.ProductId;
productDetailDTO.Name = item.Name;
productDetailDTO.Category = item.ProductCategory.Name;
productDetailDTO.Description = item.Description;
productDetailDTO.Brand = item.Brand;
productDetailDTO.Image = item.ProductImages.ElementAt(0).Image;
productDetailDTO.Variants = item.ProductVariantMappings
.GroupBy(pm => pm.GUID)
.Select(g => new Variant
{
Guid = g.Key,
// Here should be some logic for getting a name of the combination of Variants
// I just take first
Name = g.FirstOrDefault()?.ProductVariant?.Name,
// Here should be some logic for getting a value of the combination of Variants
// Take first again
Value = g.FirstOrDefault()?.Value,
Price = // need inventory table to compute price
})
.ToList();
}
}
Also note that you need somehow add relation to inventory table, which is not presented in question. Hope it helps.

Entity framework navigation property is null

I have two models using Entity Framework.
public class Player
{
public int PlayerId { get; set; }
public string Name { get; set; }
public string Sex { get; set; }
public string Plays { get; set; }
public string FavouriteSurface { get; set; }
}
public class SinglesMatch
{
public int SinglesMatchId { get; set; }
public int Player1Id { get; set; }
public int Player2Id { get; set; }
public int PlayerIdWinner { get; set; }
public DateTime Date { get; set; }
public string Venue { get; set; }
public string Score { get; set; }
public List<Player> Players { get; set; }
}
I am using the below code to attempt to display the Name of the player, based on the PlayerId in the SinglesMatch model matching the PlayerID from the Player model.
#foreach (var item in #Model)
{
<ul id="Players" class="bg-success"></ul>
<br/>
<h3>Date - #Html.DisplayFor(#modelItem => item.Date)</h3>
<li>Venue - #Html.DisplayFor(#modelItem => item.Venue)</li>
<li>Player 1 - #Html.DisplayFor(#modelItem => item.Players.First(p => p.PlayerId == item.Player1Id).Name)</li>
<li>Player 2 - #Html.DisplayFor(#modelItem => item.Players.First(p => p.PlayerId == item.Player2Id).Name)</li>
<li>Score- #Html.DisplayFor(#modelItem => item.Score)</li>
}
Upon debugging, the navigation property is always showing as null when the model is retrieved from my repository.
Am I using the navigation property in the correct fashion ? is there a problem with my query ?
Edit to include DbContext:
public TennisTrackerContext() : base("name=TennisTrackerContext")
{
}
public DbSet<Player> Players { get; set; }
public DbSet<PlayerRecord> PlayerRecords { get; set; }
public DbSet<SinglesMatch> SinglesMatches { get; set; }
public DbSet<DoublesMatch> DoublesMatches { get; set; }
public DbSet<Venue> Venues { get; set; }
}
}
You need to add a bridge table. Sql will create this automatically but you won't have access to the variables unless you create it in c#.
public class Player
{
public int PlayerId { get; set; }
public string Name { get; set; }
public string Sex { get; set; }
public string Plays { get; set; }
public string FavouriteSurface { get; set; }
List<PlayerInMatch> Matches { get; set; }
public Player()
{
Matches = new List<PlayerInMatch>();
}
}
public class PlayerInMatch
{
public int Id { get; set; }
public int PlayerId { get; set; }
[ForeignKey("PlayerId")]
public Player Player { get; set; }
public int SinglesMatchId { get; set; }
[ForeignKey("SinglesMatchId")]
public SinglesMatch SinglesMatch { get; set; }
}
public class SinglesMatch
{
public int SinglesMatchId { get; set; }
public int PlayerIdWinner { get; set; }
public DateTime Date { get; set; }
public string Venue { get; set; }
public string Score { get; set; }
public List<PlayerInMatch> Players { get; set; }
public SinglesMatch()
{
Players = new List<PlayerInMatch>();
}
}
static void Main(string[] args)
{
var match = new SinglesMatch();
match.Players.Select(c => c.Player.Name);
}
You need to make your navigation property virtual to enable lazy/eager loading:
public class SinglesMatch
{
public int SinglesMatchId { get; set; }
public int Player1Id { get; set; }
public int Player2Id { get; set; }
public int PlayerIdWinner { get; set; }
public DateTime Date { get; set; }
public string Venue { get; set; }
public string Score { get; set; }
public virtual List<Player> Players { get; set; }
}
Also, did you define the relationship between SinglesMatch and Singles in fluent api?
EDIT: I see you don't have any relations mapped through annotations or fluent api whatsoever, I suggest you take a look at this:
https://msdn.microsoft.com/en-us/data/jj591617.aspx

EF update is inserting and into a different table

I have an MVC 5 website using EF6 code first.
The website will track golf results at events.
Here are my pocos:
public class Event
{
public int EventId { get; set; }
public string VenueName { get; set; }
public string CourseName { get; set; }
public String FirstTeeOff { get; set; }
public DateTime EventDate { get; set; }
public decimal Fee { get; set; }
public virtual ICollection<Result> Results { get; set; }
}
public class Golfer
{
public int GolferId { get; set; }
public string FirstName { get; set; }
public string Surname { get; set; }
public int CurrentHandicap { get; set; }
public string Email { get; set; }
public string Telephone { get; set; }
public virtual ICollection<Result> Results { get; set; }
}
public class Result
{
public int ResultId { get; set; }
public Golfer Golfer { get; set; }
public Event Event { get; set; }
public bool Attendance { get; set; }
public int HandicapPlayed { get; set; }
public int ScoreCarded { get; set; }
public int LongestDriveWins { get; set; }
public int NearestPinWins { get; set; }
public Result()
{
Event = new Event();
Golfer = new Golfer();
}
}
The POST edit action for my Result is as follows:
[HttpPost]
[Authorize]
public ActionResult Edit(ResultViewModel resultVM)
{
try
{
DomainClasses.Result resultDomain = _context.Results.Find(resultVM.GolferResults[0].ResultId);
resultDomain.Attendance = resultVM.GolferResults[0].Attendance;
resultDomain.HandicapPlayed = resultVM.GolferResults[0].HandicapPlayed;
resultDomain.ScoreCarded = resultVM.GolferResults[0].ScoreCarded;
resultDomain.LongestDriveWins = resultVM.GolferResults[0].LongestDriveWins;
resultDomain.NearestPinWins = resultVM.GolferResults[0].NearestPinWins;
_context.Results.Attach(resultDomain);
_context.SaveChanges();
return RedirectToAction("Index");
}
catch
{
return View();
}
}
I'm getting an error on the SaveChanges. I've used EF Profiler and it showed that it was trying to insert into the Event table:
INSERT [dbo].[Events]
([VenueName],
[CourseName],
[FirstTeeOff],
[EventDate],
[Fee])
VALUES (NULL,
NULL,
NULL,
'0001-01-01T00:00:00' /* #0 */,
0 /* #1 */)
SELECT [EventId]
FROM [dbo].[Events]
WHERE ##ROWCOUNT > 0
AND [EventId] = scope_identity()
Any idead why?
It's most likely because you create instances of the related entities in the Result constructor:
Event = new Event();
Golfer = new Golfer();
Remove those lines from the constructor.