My question is about how can i select some one-two column from those tables are included and at the end when i am selecting as list it is returning list of parent object but child are contain those column i mention to select?
var testq = _db.Homes
.Include(x => x.Indexs.Cities.Proviences.Regions)
.Include(x => x.Images)
.Select(x => new Homes {
Images = x.Images,
Address = x.Address,
Indexs.Cities.Proviences.Regions =
x.Indexs.Cities.Proviences.Regions.Name });
At the end I need to have list of home model (List) and just images and Address and region name have value and important just those are selected from database not all infromation in the tables. I am trying to make a query with better performance
Edit Add Models
public partial class dbContext : DbContext
{
public virtual DbSet<City> Cities { get; set; }
public virtual DbSet<Province> Provinces { get; set; }
public virtual DbSet<Region> Regions { get; set; }
public virtual DbSet<Index> Indexs { get; set; }
public virtual DbSet<Home> Homes { get; set; }
public virtual DbSet<Images> Imageses { get; set; }
}
public partial class Home
{
public Home()
{
Imageses = new HashSet<Images>();
}
[Key]
public int IDHome { get; set; }
[Required]
[StringLength(5)]
public string Cap { get; set; }
[Required]
[StringLength(10)]
public string Number { get; set; }
[Required]
[StringLength(50)]
public string Address { get; set; }
....
public virtual Index Indexs { get; set; }
public virtual ICollection<Images> Imageses { get; set; }
}
public class Index
{
public int ID { get; set; }
public int IDHome { get; set; }
....
public virtual City Cities { get; set; }
}
public partial class City
{
[Key]
public int ID { get; set; }
public int IDProvincia { get; set; }
public decimal Latitudine { get; set; }
public decimal Longitudine { get; set; }
[Required]
[StringLength(100)]
public string Name { get; set; }
....
public virtual Province Provinces { get; set; }
}
public partial class Province
{
[Key]
public int ID { get; set; }
public int IDRegione { get; set; }
[Required]
[StringLength(50)]
public string Name { get; set; }
[Required]
[StringLength(3)]
public string Init { get; set; }
...
public virtual Region Regions { get; set; }
}
public partial class Region
{
[Key]
public int ID { get; set; }
[Required]
[StringLength(50)]
public string Name { get; set; }
public DateTime DataInsert { get; set; }
...
}
public class Images
{
public int ID { get; set; }
public string Path { get; set; }
...
}
absolutely tables have more column just add here as example
you have to define a new type with the fields you need, or use an anonymous type.
.Select(x => new {
Images = x.Images,
Address = x.Address,
Indexs.Cities.Proviences.Regions =
x.Indexs.Cities.Proviences.Regions.Name });
Related
I have in database two tables: product, supplier
I want the entity framework to define the supplier of each product
I am getting data successfully for two tables but the supplier in the product table is null.
Also, the products collection in the supplier table is null.
this is my product class:
public class Product
{
public int id { get; set; }
[Column("Productname", TypeName = "ntext")]
public string Name { get; set; }
public decimal UnitPrice { get; set; }
public bool isDiscounted { get; set; }
public int quantity { get; set; }
public int SupplierId { get; set; }
[ForeignKey("SupplierId")]
public Supplier supplier { get; set; }
}
this is the class of supplier:
public class Supplier
{
public int Id { get; set; }
public string CompanyName { get; set; }
public string ContactName { get; set; }
public string ContactTitle { get; set; }
public string city { get; set; }
public string country { get; set; }
public string phone { get; set; }
public string Fax { get; set; }
public List<Product> Products { get; set; }
}
context class:
public class DbConext : DbContext
{
public DbSet<Product> Products { get; set; }
public DbSet<Supplier> Suppliers { get; set; }
public DbConext(DbContextOptions<DbConext> options) : base(options)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Product>().ToTable("Product");
modelBuilder.Entity<Supplier>().ToTable("Supplier");
modelBuilder.Entity<Product>().HasKey("id");
modelBuilder.Entity<Supplier>().HasKey("Id");
modelBuilder.Entity<Product>().HasOne(p => p.supplier).WithMany(s => s.Products).HasForeignKey(p => p.SupplierId);
}
}
This article might help.
You should use .Include() to load any related properties.
minimum you need is to initialize the list
public class Supplier
{
public int Id { get; set; }
public string CompanyName { get; set; }
public string ContactName { get; set; }
public string ContactTitle { get; set; }
public string city { get; set; }
public string country { get; set; }
public string phone { get; set; }
public string Fax { get; set; }
public List<Product> Products { get; set; }
public Supplier() {
this.Products = new List<Product>();
}
}
I have two classes:
One is User
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public List<Subscription> Subscriptions { get; set; }
}
Other is Subscription:
public class Subscription
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
}
As you can see that User has a list of Subscriptions.
Now when using the entity framework code first approach I am getting a table for User which doesn't contain Subscriptions but a new column for User Id is being added to Subscription table. I was expecting to have a third table which contains two columns one with User ID and the other with subscription ID.
How can I achieve this?
From documentation:
Many-to-many relationships without an entity class to represent the join table are not yet supported. However, you can represent a many-to-many relationship by including an entity class for the join table and mapping two separate one-to-many relationships.
So this answer is correct.
I just corrected code a little bit:
class MyContext : DbContext
{
public DbSet<Use> Users { get; set; }
public DbSet<Subscription> Subscriptions { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<UserSubscription>()
.HasKey(t => new { t.UserId, t.SubscriptionId });
modelBuilder.Entity<UserSubscription>()
.HasOne(pt => pt.User)
.WithMany(p => p.UserSubscription)
.HasForeignKey(pt => pt.UserId);
modelBuilder.Entity<UserSubscription>()
.HasOne(pt => pt.Subscription)
.WithMany(t => t.UserSubscription)
.HasForeignKey(pt => pt.SubscriptionId);
}
}
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public List<UserSubscription> UserSubscriptions{ get; set; }
}
public class Subscription
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
public List<UserSubscription> UserSubscriptions{ get; set; }
}
public class UserSubscription
{
public int UserId { get; set; }
public User User { get; set; }
public int SubscriptionId { get; set; }
public Subscription Subscription { get; set; }
}
PS. You don't need use virtual in navigation property, because lazy loading still not available in EF Core.
Create a third middle table named: UserSubscriptions for example.
public class User
{
public int ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public virtual ICollection<UserSubscription> Subscriptions { get; set; }
}
public class Subscription
{
public int ID { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
}
public class UserSubscription
{
public int ID { get; set; }
public int SubscriptionID { get; set; }
public decimal Price { get; set; }
public int UserID { get; set; }
public virtual User { get; set; }
public DateTime BeginDate { get; set; }
public DateTime EndDate { get; set; }
}
Second Solution:
Add reference for Subscription to User and name it CurrentSubscription for example.
public class User
{
public int ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public int CurrentSubscriptionID { get; set; }
public virtual Subscription Subscription { get; set; }
}
public class Subscription
{
public int ID { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
}
Previous question link
Consider to my previous question (I put a link to it) I need to get some different information.
Here is a DB structure I only added navigation property
public virtual ICollection<Accident> Accidents { get; set; }
to Transport class
public class Person
{
[Key]
public int PersonID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public class Transport
{
[Key]
public int TransportID { get; set; }
public string Model { get; set; }
public string Brand { get; set; }
public virtual ICollection<Accident> Accidents { get; set; }
}
public class Accident
{
[Key]
public int AccsidentID { get; set; }
public DateTime AccidentDate { get; set; }
public int TransportID { get; set; }
[ForeignKey("TransportID")]
public virtual Transport Transport { get; set; }
public int PersonID { get; set; }
[ForeignKey("PersonID")]
public virtual Person Person { get; set; }
}
public class AccsidentObject
{
[Key]
public int AccidentID { get; set; }
public DateTime AccidentDate { get; set; }
public int TransportID { get; set; }
public string Model { get; set; }
public string Brand { get; set; }
public int PersonID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
If I want to get all accidents I use
var accidents = DBContext.Accidents.Select( a => new AccidentObject
{
AccidentID = a.AccidentId,
AccidentDate
TransportID
Model
Brand = a.Transport.Brand,
PersonID = a.Person.PersonID,
FirstName
LastName
});
What would be a code if I would like to select TransportObject with added specific Accident data
public class TransportObject
{
[Key]
public int TransportID { get; set; }
public string Model { get; set; }
public string Brand { get; set; }
public int AccidentID { get; set; }
public DateTime AccidentDate { get; set; }
}
Use this code
var transports = DBContext.Transports
.SelectMany(
x => x.Accidents,
(t, a) => new TransportObject
{
TransportID = t.TransportID,
Model = t.Model,
Brand = t.Brand,
AccidentID = a.AccidentId,
AccidentDate = a.AccidentDate
}
);
More about select many in MSDN.
Hi guys I am spinning wheels on this one. I am using EF6 and ASP.Net 4.6. I have a given table which has student information and parent information. A student can have many parents and a parent can have many students. Call this table 'Contact'. I am to create a table called 'Request' which will hold information for a parent submitting a request for his student. I will create a lookup table with two columns, one for student id and one for parent id called 'StudentParents'. I want to be able to have the parent log in, select his student from a drop down of all of his students and submit the request. The many to many relationship is throwing me off as far as my include statements. How can I get EF to set up this structure so that when I GetRequest(id) I can get the Student info and the Parent info to be included? Here is my code that wont Include anything other than the request.
public class Contact
{
[Key]
public int id { get; set; }
public string student_id { get; set; }//This is the Student ID
public string last_name { get; set; }
public string first_name { get; set; }
public string middle_initial { get; set; }
public string grade { get; set; }
public int current_school_id { get; set; }
public string current_school_name { get; set; }
[Display(Name = "Parent Last Name")]
public string contact_first_name { get; set; }
[Display(Name = "Parent Middle Name")]
public string contact_middle_name { get; set; }
[Display(Name = "Parent Last Name")]
public string contact_last_name { get; set; }
public string contact_relationship { get; set; }
[Display(Name = "Parent Email")]
public string contact_email { get; set; }
[Display(Name = "Parent Address")]
public string login { get; set; }//This is the Parent ID
public string Classif_description { get; set; }
}
public class Request
{
[Key]
public int id { get; set; }
public Student student_id { get; set; }
public Contact login { get; set; }
[Display(Name = "First School Choice")]
public string firstSchool { get; set; }
[Display(Name = "Second School Choice")]
public string secSchool { get; set; }
[Display(Name = "Rising Grade")]
public string rising_grade { get; set; }
public DateTime ReqSubmitted { get; set; }
public string ReqStatus { get; set; }
public DateTime Created { get; set; }
public DateTime Modified { get; set; }
public string ModifBy { get; set; }
}
public class Parent
{
public int id { get; set; }
public string contact_first_name { get; set; }
public string contact_middle_name { get; set; }
public string contact_last_name { get; set; }
public string contact_relationship { get; set; }
public string contact_email { get; set; }
public string contact_address { get; set; }
public string contact_city { get; set; }
public string contact_zip { get; set; }
[Key]
public string login { get; set; }
public string contact_pw { get; set; }
public string phone { get; set; }
public string phone_type { get; set; }
public Parent() { }
public virtual ICollection<Student> Students { get; set; }
}
public class Student
{
[Key]
public int id { get; set; }
public int student_id { get; set; }
public string last_name { get; set; }
public string first_name { get; set; }
public string middle_initial { get; set; }
public DateTime birthdate { get; set; }
public string gender { get; set; }
public string grade { get; set; }
public string Fed_race_description { get; set; }
public string Classif_description { get; set; }
public int current_school_id { get; set; }
public string current_school_name { get; set; }
public int home_school_id { get; set; }
public string home_school_name { get; set; }
public Student()
{
this.Parents = new HashSet<Parent>();
}
public virtual ICollection<Parent> Parents { get; set; }
}
public class OEContext : DbContext
{
public OEContext() : base("name=OEContext")
{
}
public DbSet<Request> Requests { get; set; }
public DbSet<Parent> Parents { get; set; }
public DbSet<Contact> Contacts { get; set; }
public DbSet<Student> Students { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Parent>()
.HasMany(s => s.Students)
.WithMany()
.Map(x =>
{
x.MapLeftKey("login");
x.MapRightKey("student_id");
x.ToTable("StudentParents");
}
);
base.OnModelCreating(modelBuilder);
}
}
Changed the strategy. Made Request have many Contacts. So I added a constructor to the request:
public Request()
{
Contacts = new List<Contact>();
}
public virtual ICollection<Contact> Contacts { get; set; }
Next I changed the contact class:
public int ContactId { get; set; }
public Contact() { }
public virtual Request Request { get; set; }
With this relationship I can pull both Parents and a student from the Contacts associated with the Request.
I have few Domain Models - Address, Customer, Employee, StoreLocation. Address has many to one relationship with Customerand Employee and one to one relationship with StoreLocation.
public class Address
{
public int Id;
public string Line1 { get; set; }
public string Line2 { get; set; }
public string Line3 { get; set; }
}
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public IList<Address> Addresses { get; set; }
}
public class StoreLocation
{
public int Id { get; set; }
public string ShortCode { get; set; }
public string Description { get; set; }
public Address Address { get; set; }
}
public class Employee
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime Dob { get; set; }
public IList<Address> Addresses { get; set; }
}
How to Map this relationship?. I am using ASP.NET MVC 3.0 and Entity Framework 4.1.
If you are using code-first (I think you want this, else, you have to edit your Q), the first way is the way explained below:
Entities:
public class Address {
[Key]
public int Id { get; set; }
public string Line1 { get; set; }
public string Line2 { get; set; }
public string Line3 { get; set; }
public virtual Customer Customer { get; set; }
public virtual StoreLocation StoreLocation { get; set; }
public virtual Employee Employee { get; set; }
public int? CustomerId { get; set; }
public int? EmployeeId { get; set; }
}
public class Customer {
[Key]
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Address> Addresses { get; set; }
}
public class StoreLocation {
[Key]
public int Id { get; set; }
public string ShortCode { get; set; }
public string Description { get; set; }
public virtual Address Address { get; set; }
}
public class Employee {
[Key]
public int Id { get; set; }
public string Name { get; set; }
public DateTime Dob { get; set; }
public virtual ICollection<Address> Addresses { get; set; }
}
DbContext inherited class:
public class ManyOneToManyContext : DbContext {
static ManyOneToManyContext() {
Database.SetInitializer<ManyOneToManyContext>(new ManyOneToManyInitializer());
}
public DbSet<Address> Addresses { get; set; }
public DbSet<Customer> Customers { get; set; }
public DbSet<StoreLocation> StoreLocations { get; set; }
public DbSet<Employee> Employees { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<IncludeMetadataConvention>();
modelBuilder.Entity<Customer>().HasMany(c => c.Addresses).WithOptional(a => a.Customer).HasForeignKey(a => a.CustomerId);
modelBuilder.Entity<StoreLocation>().HasRequired(s => s.Address).WithOptional(a => a.StoreLocation).Map(t => t.MapKey("AddressId"));
modelBuilder.Entity<Employee>().HasMany(e => e.Addresses).WithOptional(a => a.Employee).HasForeignKey(e => e.EmployeeId);
}
}
Context Initializer:
public class ManyOneToManyInitializer : DropCreateDatabaseAlways<ManyOneToManyContext> {
protected override void Seed(ManyOneToManyContext context) {
}
}
That will create the db-schema below:
Let me know if you have any questions or need clarifications on any part.