I am trying to get my data from database to display on my view. Currently on my database table there are these columns: ID, ReportDescription, DateReported, CustomerId and MovieId.
What I need to do is use the CustomerId and MovieId to get to the name of the Customer and the name of the Movie.
This is my Model:
public class Malfunction
{
public int Id { get; set; }
[Required]
public Movie Movie { get; set; }
[Required]
public Customer Customer { get; set; }
[Required]
[StringLength(255)]
public string ReportDescription { get; set; }
public DateTime DateReported { get; set; }
}
This is the Controller:
private ApplicationDbContext _context;
public TablesController()
{
_context = new ApplicationDbContext();
}
// GET: Tables
public ActionResult MalfunctionsList(MalfunctionDTO malfunctionDTO)
{
var malfunctions = _context.Malfunctions.ToList();
return View(malfunctions);
}
}
And this is the DTO:
public class MalfunctionDTO
{
public int CustomerId { get; set; }
public List<int> MovieIds { get; set; }
public Customer Customer { get; set; }
public Movie Movie { get; set; }
public string ReportDescription { get; set; }
}
IdentityModel:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public DbSet<MembershipType> MembershipTypes { get; set; }
public DbSet<Movie> Movies { get; set; }
public DbSet<Customer> Customers { get; set; }
public DbSet<Genre> Genres { get; set; }
public DbSet<Rent> Rents { get; set; }
public DbSet<Malfunction> Malfunctions { get; set; }
Am i supposed to add properties like CustomerId and MovieId in my model in order for it to work?
Worth noting that i am very new to MVC and EF, so forgive me if I am a bit confused.
Your need to change your mapping to look like below.
// For Id
Mapper.CreateMap<Malfunction, MalfunctionDTO>()
.ForMember(dest => dest.CustomerId,
opt => opt.MapFrom(src => src.Id));
Update
I assume you are not using Entity Framework Core.
Update your context like below. vrtual key word added.
public virtual DbSet<Movie> Movies { get; set; }
public virtual DbSet<Customer> Customers { get; set; }
Also change
public class Malfunction
{
public int Id { get; set; }
[Required]
public virtual Movie Movie { get; set; }
[Required]
public virtual Customer Customer { get; set; }
[Required]
[StringLength(255)]
public string ReportDescription { get; set; }
public DateTime DateReported { get; set; }
}
Then you may need to add configuration in your OnModelCreatingmethod something like this.Try without this first, if not work then add below configurations.
modelBuilder.Entity()
.WithRequired(m => m.Movie);
modelBuilder.Entity()
.WithRequired(m => m.Customer);
Related
i am designing a system and one of my entity has one to many relation as shown below.
public class Product
{
public int Id { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public Product Product { get; set; }
}
competitorProduct indicates that product has a equivalent which is sold by different store. should i define one-to-many relation as shown above or below? which one is correct?
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts{ get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
}
Assuming it is a one to many relationship (what would happen if a competitor product was competing with more than one of your products for example) you can do both and add in a foreign key as well.
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public int ProductId { get; set; }
public virtual Product Product { get; set; }
}
You can then set up your relationship using fluent API as so:
modelBuilder.Entity<CompetitorProduct>(entity =>
{
entity.HasOne(e => e.Product)
.WithMany(e => e.CompetitorProducts)
.HasForeignKey(e => e.ProductId)
.HasConstraintName("FK_ComptetitorProduct_Product");
});
This way you can access the competitor products from the product and the product from the competitor products.
Here is a quick example of a ecommerce site I have worked on and how we did table relations.
I removed a bunch of the fields so you can see what you really need. Once to make relations and run Add-Migration EF will handle the FK constraints for you as long as you identified them in models like how I have below.
public class ApplicationUser : IdentityUser
{
public ApplicationUser()
{
Active = true;
CreateDateTimeUtc = DateTime.UtcNow;
ModifiedDateTimeUtc = DateTime.UtcNow;
}
[StringLength(500)]
public string FirstName { get; set; }
[StringLength(500)]
public string LastName { get; set; }
[StringLength(1000)]
public string Address { get; set; }
[StringLength(100)]
public string Unit { get; set; }
[StringLength(250)]
public string City { get; set; }
[StringLength(25)]
public string State { get; set; }
[StringLength(20)]
public string ZipCode { get; set; }
//This will give access to a list of child carts a user could have
[Index]
public bool Active { get; set; }
public virtual ICollection<Cart> Carts { get; set; }
// Account Profile Image
public byte[] ProfileImage { get; set; }
[StringLength(500)]
public string ProfileFilename { get; set; }
[StringLength(100)]
public string ProfileMimeType { get; set; }
}
[Table("Cart", Schema = "dbo")]
public class Cart : AbstractTable
{
public Cart()
{
IsComplete = false;
}
//This create relation to user table where I can get one unique user.
[StringLength(128)]
[ForeignKey("ApplicationUser")]
public string UserId { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
//These link us to child tables of Cart where we can get a LIST of the items below
public virtual ICollection<CartCategory> CartCategories { get; set; }
public virtual ICollection<CartItem> CartItems { get; set; }
// Marked when a payment/receipt is generated based off of this cart
public bool IsComplete { get; set; }
}
[Table("CartItem", Schema = "dbo")]
public class CartItem : AbstractTable
{
//This will return one unique cart id and let us access it as the parent record
[ForeignKey("Cart")]
public Guid CartId { get; set; }
public virtual Cart Cart { get; set; }
// Signifies if this was paid for in a receipt
public bool IsComplete { get; set; }
public virtual ICollection<CartItemCustomField> CustomFields { get; set; }
}
I am getting confused with my LINQ query and wondering if there is a way I can achieve the following:
A user has a list of liked Categories:
public class ApplicationUser : IdentityUser
{
[PersonalData]
public string Name { get; set; }
[PersonalData]
[DataType(DataType.Date)]
public DateTime DOB { get; set; }
[PersonalData]
public PersonGender Gender { get; set; }
[PersonalData]
[ForeignKey("Suburb")]
public int SuburbId { get; set; }
//Information about user preferences
public ICollection<UserCategory> LikedCategories { get; set; }
public virtual Suburb Suburb { get; set; }
}
Where UserCategory is defined as follows:
public class UserCategory
{
[Key]
public int Id { get; set; }
public ApplicationUser applicationUser { get; set; }
public Category Category { get; set; }
[ForeignKey("ApplicationUser")]
public string applicationUserId { get; set; }
[ForeignKey("Category")]
public int CategoryId { get; set; }
}
And Category is:
public class Category
{
[Key]
public int ID { get; set; }
public string Name { get; set; }
public int CategoryFollowers { get; set; }
public ICollection<EventCategory> EventCategories { get; set; }
public ICollection<UserCategory> UserCategories { get; set; }
}
}
Finally, in my Events class I have the following:
public class Event
{
[Key]
public int ID { get; set; }
[Required]
public string Name { get; set; }
[Display(Name = "Is Featured?")]
public bool isFeatured { get; set; }
public byte[] EventImage1 { get; set; }
public byte[] EventImage2 { get; set; }
public virtual ICollection<EventCategory> EventCategories { get; set; }
public virtual ICollection<UserEvent> UserEvents { get; set; }
My view requires an object of type Event, so I am trying to return a list of Events where the EventCategory is contained in the UserCategory table. In other words I just want to show events that the user has liked the category for.
MORE CLARIFICATION
I am able to filter my events by category from a different function that takes in a hardcoded category Id from the view and this works fine:
//GET:// Browse event by category
public async Task<IActionResult> BrowseByCategory(int? id, int? alt_id)
{
if (id == null)
{
return NotFound();
}
var eventsContext = _context.Events
.Include(m => m.Venue)
.ThenInclude(mf => mf.Suburb)
.ThenInclude(mc => mc.Constituency)
.ThenInclude(md => md.City)
.Where(e => e.EventCategories.Any(c => c.Category.ID == id || c.Category.ID == alt_id))
.Take(15)
.OrderByDescending(o => o.StartDate);
return View("Browse",await eventsContext.ToListAsync());
}
I would like to do the exact same as above, but rather than pass in the hardcoded ID queries from the form, I want the query to check the categoryIDs that are saved in the UserCategory table. There is no set number of how many UserCategory items there are.
Say if I have the classic example of Student and Courses. A student can have many courses and course can have many students.
How do I make the middle table in EF 6 code if I wanted to add an extra field on the many table part?
Do I just make in code another class and then hook it up somehow?
DB Context
public class MyContext : DbContext
{
public MyContext (string nameOrConnectionString) : base(nameOrConnectionString)
{
// this.Configuration.ProxyCreationEnabled = false;
Database.SetInitializer(new CreateDatabaseIfNotExists<OSPContext>());
}
public DbSet<Student> Students { get; set; }
public DbSet<Course> Courses { get; set; }
public DbSet<StudentCourse> StudentCourses { get; set; }
}
public class StudentCourse
{
[Key]
public Guid StudentCourseId { get; set; }
public Guid StudentId { get; set; }
[ForeignKey("StudentId")]
public virtual Student Student { get; set; } // Include this so you can access it later
public Guid CourseId { get; set; }
[ForeignKey("CourseId")]
public virtual Course Course { get; set; }
public int Permissions { get; set; }
}
public class Course
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Student> Students { get; set; } = new >();
}
public class Student
{
[Key]
public Guid Id { get; set; }
public string Email { get; set; }
public virtual ICollection<Course> Courses { get; set; } = new List<Course>();
}
Given you are code first I would do something like the following.
public class Student
{
[Key]
public int StudentId { get; set; }
public string Name { get; set; }
public List<StudentCourse> Courses { get; set; } // So you can access Courses for a student
}
public class Course
{
[Key]
public int CourseId { get; set; }
public string Name { get; set; }
public List<StudentCourse> Students { get; set; }
}
public class StudentCourse
{
[Key]
public int StudentCourseId { get; set; }
public int StudentId { get; set; }
[ForeignKey("StudentId")]
public Student Student { get; set; } // Include this so you can access it later
public int CourseId { get; set; }
[ForeignKey("CourseId")]
public Course Course { get; set; }
}
EDIT: Wanted to note relationships are established with Data Attributes, you could also use EF Fluent API to establish your relationships. The properties will look the same, but without the [ForeignKey("")]
I am trying to update an record in my system. Everything on the model saves great, except any of my many to many type relationships on the form. When I get to those in my model it gives me the error. "The member with identity 'PmData.SafetyRequirement_Assets' does not exist in the metadata collection.\r\nParameter name: identity". I've read over some of the other answers but I do not have any triggers on my database, and I've gone through several changes in my model based on other suggestions and it doesn't seem to change anything. The project is in vNext.
Here is my first model
public partial class Asset : DataModel
{
[Required]
[StringLength(64)]
public string Name { get; set; }
[StringLength(256)]
public string Description { get; set; }
[StringLength(1024)]
public string SystemFunction { get; set; }
[StringLength(2048)]
public string Remarks { get; set; }
public bool IsSystem { get; set; }
public bool IsGrouping { get; set; }
[StringLength(128)]
public string FieldTag { get; set; }
[ForeignKey("Parent")]
public int? ParentId { get; set; }
[ForeignKey("Building")]
public int? BuildingId { get; set; }
public bool IsOperable { get; set; }
public bool IsAvailable { get; set; }
public virtual Asset Parent { get; set; }
public virtual Building Building { get; set; }
public virtual ICollection<Asset> Children { get; set; }
public virtual ICollection<DrawingReference> DrawingReferences { get; set; }
public virtual ICollection<SpecReference> SpecReferences { get; set; }
public virtual ICollection<SafetyRequirement> SafetyRequirements { get; set; }
public virtual ICollection<SupportSystem> SupportSystems { get; set; }
}
The model for one the other table with a many to many.
public partial class SafetyRequirement : DataModel
{
[StringLength(256)]
[Required]
public string Name { get; set; }
[StringLength(2048)]
public string SafetyFunction { get; set; }
[StringLength(2048)]
public string FunctionalRequirements { get; set; }
[StringLength(2048)]
public string SystemBoundary { get; set; }
[StringLength(255)]
public string Reference { get; set; }
[ForeignKey("QualityLevel")]
public int QualityLevelId { get; set; }
public virtual QualityLevel QualityLevel { get; set; }
public virtual ICollection<Asset> Assets { get; set; }
}
The map for the joining table
modelBuilder.Entity<Asset>().HasMany(t => t.SafetyRequirements)
.WithMany(t => t.Assets)
.Map(m =>
{
m.MapRightKey("SafetyRequirementId");
m.MapLeftKey("AssetId");
m.ToTable("AssetSafetyRequirement");
});
Finally here's the area that it fails...
public virtual void SaveAsync(TEntity model)
{
Task.Run(() =>
{
using (
var dbContext =
(TContext)
Activator.CreateInstance(typeof (TContext),
ConfigOptions == null ? ConfigService.ConnectionString : ConfigOptions.ConnectionString))
{
var dbSet = dbContext.Set<TEntity>();
dbSet.Attach(model);
dbContext.Entry(model).State = EntityState.Modified;
dbContext.SaveChanges();
}
});
}
Any information or pointers would be greatly appreciated.
You're trying to use both Fluent API and Data Annotations to define the relationships between your tables. Remove one or the other.
My "ShoppingCart" and "ShoppingCartItems" tables are already in my database. I am trying to add a new table called "discountCodes". Each shoppingCart can have one or zero discountCodes.
The error I am receiving is: Invalid column name 'discountId'.
[Table("ShoppingCarts")]
public class ShoppingCart
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
[Column("cartID")]
public string cartID { get; set; }
public virtual IList<ShoppingCartItem> CartItems { get; set; }
[Column("dateCreated")]
public DateTime? DateCreated { get; set; }
[Column("userID")]
public Guid UserID { get; set; }
public int? discountId { get; set; }
public virtual Discount discount { get; set; }
}
[Table("discountCodes")]
public class Discount
{
public int discountId { get; set; }
public string discountCode{get;set;}
[Required]
public int percentOff { get; set; }
[Required]
public Boolean isActive { get; set; }
public ShoppingCart ShoppingCart { get; set; }
}
public class ShoppingCartContext : DbContext
{
public ShoppingCartContext()
: base("MYDBConnectionString")
{
Database.SetInitializer<ShoppingCartContext>(new CreateDatabaseIfNotExists<ShoppingCartContext>());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<ShoppingCart>().HasKey(t => t.cartID)
.HasOptional(t => t.discount)
.WithOptionalPrincipal(d => d.ShoppingCart)
.Map(t => t.MapKey("cartID"));
modelBuilder.Entity<Discount>().HasKey(t => t.discountId)
.HasOptional(q => q.ShoppingCart);
}
public DbSet<Discount> discountCodes { get; set; }
public DbSet<ShoppingCart> ShoppingCart { get; set; }
public DbSet<ShoppingCartItem> ShoppingCartItems { get; set; }
}
If you are working on an existing database you have to implement a DbMigration like it's explain here: Code First Migrations.
If you are in development phase, the easiest way is to drop the database.