Entity Framework Core Code-First Tutorial

This tutorial guides you through the process of creating a simple application powered by Entity Framework Core. This application will create tables in the database based on the model in run-time, fill them with sample data, and execute queries.

Requirements

If you want to target Entity Framework Core 2.0, this tutorial requires the following:

  • Visual Studio 2017 or higher
  • .NET Core SDK 2.0
  • .NET Framework 4.6.1 or higher

dotConnect for SQLite

This article uses classes from dotConnect for SQLite, a high-performance ADO.NET provider with the ORM support (Entity Framework, NHibernate, and LinqConnect).

Try code examples from this article yourself!

*Trial and free versions are available

If you want to target Entity Framework Core 1.1, this tutorial requires the following:

  • Visual Studio 2013 or higher
  • .NET Framework 4.5.1 or higher

Note that Entity Framework support is available only in Professional Edition of dotConnect for SQLite.

Creating Application

To create the sample application, let's perform the following steps:

  1. Create a new console application.
  2. For Entity Framework Core 2.0, ensure that you are targeting .NET Framework 4.6.1 or later. For Entity Framework Core 1.1, ensure that you are targeting .NET Framework 4.5.1 or later.
  3. Install the Entity Framework Core NuGet package by executing the following command in the Package Manager Console (for Entity Framework Core 2.0):
    Install-Package Microsoft.EntityFrameworkCore.Relational


    For Entity Framework Core 1.1, the command will be the following:
    Install-Package Microsoft.EntityFrameworkCore.Relational -Version 1.1.4
  4. Additionally you need to add references to the following assemblies to your project:

    • Devart.Data.dll
    • Devart.Data.SQLite.dll
    • Devart.Data.SQLite.Entity.EFCore.dll

    Please note that there are two versions of Devart.Data.SQLite.Entity.EFCore.dll assemblies - for Entity Framework Core 2.0 and for Entity Framework Core 1.1. The first is located in the \Entity\EFCore2 subfolder of the dotConnect for SQLite installation folder, and the second one - in the \Entity\EFCore subfolder.

  5. Create a DbContext descendant.

    [C#]
    using Microsoft.EntityFrameworkCore;
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data;
    using System.IO;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
     
    public class MyDbContext : DbContext {
     
    }
    
    [Visual Basic]
    Imports Microsoft.EntityFrameworkCore
    Imports System.Collections.Generic
    Imports System.ComponentModel.DataAnnotations
    Imports System.ComponentModel.DataAnnotations.Schema
    Imports System.Data
    Imports System.IO
    Imports System.Linq
    Imports System.Text
    Imports System.Threading.Tasks
    
    Public Class MyDbContext
    	Inherits DbContext
    
    End Class
    
  6. Register Entity Framework Core provider for using with our DbContext and specify the connection string. For this override the OnConfiguring method.

    [C#]
    public class MyDbContext : DbContext {
     
      protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
    
         optionsBuilder.UseSQLite(@"DataSource=mydatabase.db;");
      } 
    }
    [Visual Basic]
    Public Class MyDbContext
    	Inherits DbContext
    
    	Protected Overrides Sub OnConfiguring(optionsBuilder As DbContextOptionsBuilder)
    
    		optionsBuilder.UseSQLite("DataSource=mydatabase.db;")
    	End Sub
    End Class
    
  7. Create entity classes, used in the model. If necessary, set DataAnnotation attributes for the classes and properties.

    [C#]
      [Table("Product")]
      public class Product {
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long ProductID { get; set; }
     
        [Required]
        [MaxLength(50)]
        public string ProductName { get; set; }
     
        public string UnitName { get; set; }
        public int UnitScale { get; set; }
        public long InStock { get; set; }
        public double Price { get; set; }
        public double DiscontinuedPrice { get; set; }
     
        public virtual ProductCategory Category { get; set; }
        public virtual ICollection<OrderDetail> OrderDetails { get; set; }
      }
     
      [Table("ProductCategory")]
      public class ProductCategory {
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long CategoryID { get; set; }
     
        [Required]
        [MaxLength(20)]
        public string CategoryName { get; set; }
     
        public virtual ProductCategory ParentCategory { get; set; }
        public virtual ICollection<ProductCategory> ChildCategories { get; set; }
        public virtual ICollection<Product> Products { get; set; }
      }
     
      [Table("Order Details")]
      public class OrderDetail {
     
        [Column(Order = 1)]
        public long OrderID { get; set; }
     
        [Column(Order = 2)]
        public long ProductID { get; set; }
     
        public double Price { get; set; }
        public double Quantity { get; set; }
     
        public virtual Product Product { get; set; }
        public virtual Order Order { get; set; }
      }
     
      [Table("Orders")]
      public class Order {
     
        public Order() {
     
          OrderDate = DateTime.Now;
        }
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long OrderID { get; set; }
     
        [Required]
        public DateTime OrderDate { get; set; }
     
        public double Freight { get; set; }
        public DateTime? ShipDate { get; set; }
        public Double Discount { get; set; }
     
        public virtual ICollection<OrderDetail> OrderDetails { get; set; }
     
        [InverseProperty("Orders")]
        public virtual PersonContact PersonContact { get; set; }
     
        public virtual Company Company { get; set; }
     
        public virtual Company ShipCompany { get; set; }
      }
     
      [Table("Company")]
      public class Company {
     
        public Company() {
        }
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long CompanyID { get; set; }
     
        [Required]
        [MaxLength(40)]
        public string CompanyName { get; set; }
     
        [MaxLength(100)]
        public string Web { get; set; }
     
        [MaxLength(50)]
        public string Email { get; set; }
     
        public virtual AddressType Address { get; set; }
     
        [InverseProperty(nameof(Order.Company))]
        public virtual ICollection<Order> Orders { get; set; }
     
        [InverseProperty(nameof(Order.ShipCompany))]
        public virtual ICollection<Order> ShippedOrders { get; set; }
     
        [InverseProperty(nameof(PersonContact.Companies))]
        public virtual PersonContact PrimaryContact { get; set; }
     
        [InverseProperty(nameof(PersonContact.Company))]
        public virtual ICollection<PersonContact> Contacts { get; set; }
     
      }
     
      [Table("Person Contact")]
      public class PersonContact {
     
        public PersonContact() {
        }
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long ContactID { get; set; }
     
        [MaxLength(8)]
        public string Title { get; set; }
     
        [MaxLength(50)]
        public string FirstName { get; set; }
     
        [MaxLength(50)]
        public string MiddleName { get; set; }
     
        [MaxLength(50)]
        public string LastName { get; set; }
     
        [MaxLength(25)]
        public string HomePhone { get; set; }
     
        [MaxLength(25)]
        public string MobilePhone { get; set; }
     
        public virtual AddressType Address { get; set; }
     
        public virtual ICollection<Order> Orders { get; set; }
        public virtual Company Company { get; set; }
        public virtual ICollection<Company> Companies { get; set; }
      }
     
      [Table("AddressType")]
      public class AddressType {
     
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public long Id { get; set; }
     
        [MaxLength(120)]
        public string AddressTitle { get; set; }
     
        [MaxLength(60)]
        public string Address { get; set; }
     
        [MaxLength(30)]
        public string City { get; set; }
     
        [MaxLength(20)]
        public string Region { get; set; }
     
        [MaxLength(15)]
        public string PostalCode { get; set; }
     
        [MaxLength(20)]
        public string Country { get; set; }
     
        [MaxLength(25)]
        public string Phone { get; set; }
     
        [MaxLength(25)]
        public string Fax { get; set; }
      }
    [Visual Basic]
    <Table("Product")> _
    Public Class Product
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property ProductID() As Long
    		Get
    			Return m_ProductID
    		End Get
    		Set
    			m_ProductID = Value
    		End Set
    	End Property
    	Private m_ProductID As Long
    
    	<Required> _
    	<MaxLength(50)> _
    	Public Property ProductName() As String
    		Get
    			Return m_ProductName
    		End Get
    		Set
    			m_ProductName = Value
    		End Set
    	End Property
    	Private m_ProductName As String
    
    	Public Property UnitName() As String
    		Get
    			Return m_UnitName
    		End Get
    		Set
    			m_UnitName = Value
    		End Set
    	End Property
    	Private m_UnitName As String
    	Public Property UnitScale() As Integer
    		Get
    			Return m_UnitScale
    		End Get
    		Set
    			m_UnitScale = Value
    		End Set
    	End Property
    	Private m_UnitScale As Integer
    	Public Property InStock() As Long
    		Get
    			Return m_InStock
    		End Get
    		Set
    			m_InStock = Value
    		End Set
    	End Property
    	Private m_InStock As Long
    	Public Property Price() As Double
    		Get
    			Return m_Price
    		End Get
    		Set
    			m_Price = Value
    		End Set
    	End Property
    	Private m_Price As Double
    	Public Property DiscontinuedPrice() As Double
    		Get
    			Return m_DiscontinuedPrice
    		End Get
    		Set
    			m_DiscontinuedPrice = Value
    		End Set
    	End Property
    	Private m_DiscontinuedPrice As Double
    
    	Public Overridable Property Category() As ProductCategory
    		Get
    			Return m_Category
    		End Get
    		Set
    			m_Category = Value
    		End Set
    	End Property
    	Private Overridable m_Category As ProductCategory
    	Public Overridable Property OrderDetails() As ICollection(Of OrderDetail)
    		Get
    			Return m_OrderDetails
    		End Get
    		Set
    			m_OrderDetails = Value
    		End Set
    	End Property
    	Private Overridable m_OrderDetails As ICollection(Of OrderDetail)
    End Class
    
    <Table("ProductCategory")> _
    Public Class ProductCategory
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property CategoryID() As Long
    		Get
    			Return m_CategoryID
    		End Get
    		Set
    			m_CategoryID = Value
    		End Set
    	End Property
    	Private m_CategoryID As Long
    
    	<Required> _
    	<MaxLength(20)> _
    	Public Property CategoryName() As String
    		Get
    			Return m_CategoryName
    		End Get
    		Set
    			m_CategoryName = Value
    		End Set
    	End Property
    	Private m_CategoryName As String
    
    	Public Overridable Property ParentCategory() As ProductCategory
    		Get
    			Return m_ParentCategory
    		End Get
    		Set
    			m_ParentCategory = Value
    		End Set
    	End Property
    	Private Overridable m_ParentCategory As ProductCategory
    	Public Overridable Property ChildCategories() As ICollection(Of ProductCategory)
    		Get
    			Return m_ChildCategories
    		End Get
    		Set
    			m_ChildCategories = Value
    		End Set
    	End Property
    	Private Overridable m_ChildCategories As ICollection(Of ProductCategory)
    	Public Overridable Property Products() As ICollection(Of Product)
    		Get
    			Return m_Products
    		End Get
    		Set
    			m_Products = Value
    		End Set
    	End Property
    	Private Overridable m_Products As ICollection(Of Product)
    End Class
    
    <Table("Order Details")> _
    Public Class OrderDetail
    
    	<Column(Order := 1)> _
    	Public Property OrderID() As Long
    		Get
    			Return m_OrderID
    		End Get
    		Set
    			m_OrderID = Value
    		End Set
    	End Property
    	Private m_OrderID As Long
    
    	<Column(Order := 2)> _
    	Public Property ProductID() As Long
    		Get
    			Return m_ProductID
    		End Get
    		Set
    			m_ProductID = Value
    		End Set
    	End Property
    	Private m_ProductID As Long
    
    	Public Property Price() As Double
    		Get
    			Return m_Price
    		End Get
    		Set
    			m_Price = Value
    		End Set
    	End Property
    	Private m_Price As Double
    	Public Property Quantity() As Double
    		Get
    			Return m_Quantity
    		End Get
    		Set
    			m_Quantity = Value
    		End Set
    	End Property
    	Private m_Quantity As Double
    
    	Public Overridable Property Product() As Product
    		Get
    			Return m_Product
    		End Get
    		Set
    			m_Product = Value
    		End Set
    	End Property
    	Private Overridable m_Product As Product
    	Public Overridable Property Order() As Order
    		Get
    			Return m_Order
    		End Get
    		Set
    			m_Order = Value
    		End Set
    	End Property
    	Private Overridable m_Order As Order
    End Class
    
    <Table("Orders")> _
    Public Class Order
    
    	Public Sub New()
    
    		OrderDate = DateTime.Now
    	End Sub
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property OrderID() As Long
    		Get
    			Return m_OrderID
    		End Get
    		Set
    			m_OrderID = Value
    		End Set
    	End Property
    	Private m_OrderID As Long
    
    	<Required> _
    	Public Property OrderDate() As DateTime
    		Get
    			Return m_OrderDate
    		End Get
    		Set
    			m_OrderDate = Value
    		End Set
    	End Property
    	Private m_OrderDate As DateTime
    
    	Public Property Freight() As Double
    		Get
    			Return m_Freight
    		End Get
    		Set
    			m_Freight = Value
    		End Set
    	End Property
    	Private m_Freight As Double
    	Public Property ShipDate() As System.Nullable(Of DateTime)
    		Get
    			Return m_ShipDate
    		End Get
    		Set
    			m_ShipDate = Value
    		End Set
    	End Property
    	Private m_ShipDate As System.Nullable(Of DateTime)
    	Public Property Discount() As [Double]
    		Get
    			Return m_Discount
    		End Get
    		Set
    			m_Discount = Value
    		End Set
    	End Property
    	Private m_Discount As [Double]
    
    	Public Overridable Property OrderDetails() As ICollection(Of OrderDetail)
    		Get
    			Return m_OrderDetails
    		End Get
    		Set
    			m_OrderDetails = Value
    		End Set
    	End Property
    	Private Overridable m_OrderDetails As ICollection(Of OrderDetail)
    
    	<InverseProperty("Orders")> _
    	Public Overridable Property PersonContact() As PersonContact
    		Get
    			Return m_PersonContact
    		End Get
    		Set
    			m_PersonContact = Value
    		End Set
    	End Property
    	Private Overridable m_PersonContact As PersonContact
    
    	Public Overridable Property Company() As Company
    		Get
    			Return m_Company
    		End Get
    		Set
    			m_Company = Value
    		End Set
    	End Property
    	Private Overridable m_Company As Company
    
    	Public Overridable Property ShipCompany() As Company
    		Get
    			Return m_ShipCompany
    		End Get
    		Set
    			m_ShipCompany = Value
    		End Set
    	End Property
    	Private Overridable m_ShipCompany As Company
    End Class
    
    <Table("Company")> _
    Public Class Company
    
    	Public Sub New()
    	End Sub
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property CompanyID() As Long
    		Get
    			Return m_CompanyID
    		End Get
    		Set
    			m_CompanyID = Value
    		End Set
    	End Property
    	Private m_CompanyID As Long
    
    	<Required> _
    	<MaxLength(40)> _
    	Public Property CompanyName() As String
    		Get
    			Return m_CompanyName
    		End Get
    		Set
    			m_CompanyName = Value
    		End Set
    	End Property
    	Private m_CompanyName As String
    
    	<MaxLength(100)> _
    	Public Property Web() As String
    		Get
    			Return m_Web
    		End Get
    		Set
    			m_Web = Value
    		End Set
    	End Property
    	Private m_Web As String
    
    	<MaxLength(50)> _
    	Public Property Email() As String
    		Get
    			Return m_Email
    		End Get
    		Set
    			m_Email = Value
    		End Set
    	End Property
    	Private m_Email As String
    
    	Public Overridable Property Address() As AddressType
    		Get
    			Return m_Address
    		End Get
    		Set
    			m_Address = Value
    		End Set
    	End Property
    	Private Overridable m_Address As AddressType
    
    	<InverseProperty(nameof(Order.Company))> _
    	Public Overridable Property Orders() As ICollection(Of Order)
    		Get
    			Return m_Orders
    		End Get
    		Set
    			m_Orders = Value
    		End Set
    	End Property
    	Private Overridable m_Orders As ICollection(Of Order)
    
    	<InverseProperty(nameof(Order.ShipCompany))> _
    	Public Overridable Property ShippedOrders() As ICollection(Of Order)
    		Get
    			Return m_ShippedOrders
    		End Get
    		Set
    			m_ShippedOrders = Value
    		End Set
    	End Property
    	Private Overridable m_ShippedOrders As ICollection(Of Order)
    
    	<InverseProperty(nameof(PersonContact.Companies))> _
    	Public Overridable Property PrimaryContact() As PersonContact
    		Get
    			Return m_PrimaryContact
    		End Get
    		Set
    			m_PrimaryContact = Value
    		End Set
    	End Property
    	Private Overridable m_PrimaryContact As PersonContact
    
    	<InverseProperty(nameof(PersonContact.Company))> _
    	Public Overridable Property Contacts() As ICollection(Of PersonContact)
    		Get
    			Return m_Contacts
    		End Get
    		Set
    			m_Contacts = Value
    		End Set
    	End Property
    	Private Overridable m_Contacts As ICollection(Of PersonContact)
    
    End Class
    
    <Table("Person Contact")> _
    Public Class PersonContact
    
    	Public Sub New()
    	End Sub
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property ContactID() As Long
    		Get
    			Return m_ContactID
    		End Get
    		Set
    			m_ContactID = Value
    		End Set
    	End Property
    	Private m_ContactID As Long
    
    	<MaxLength(8)> _
    	Public Property Title() As String
    		Get
    			Return m_Title
    		End Get
    		Set
    			m_Title = Value
    		End Set
    	End Property
    	Private m_Title As String
    
    	<MaxLength(50)> _
    	Public Property FirstName() As String
    		Get
    			Return m_FirstName
    		End Get
    		Set
    			m_FirstName = Value
    		End Set
    	End Property
    	Private m_FirstName As String
    
    	<MaxLength(50)> _
    	Public Property MiddleName() As String
    		Get
    			Return m_MiddleName
    		End Get
    		Set
    			m_MiddleName = Value
    		End Set
    	End Property
    	Private m_MiddleName As String
    
    	<MaxLength(50)> _
    	Public Property LastName() As String
    		Get
    			Return m_LastName
    		End Get
    		Set
    			m_LastName = Value
    		End Set
    	End Property
    	Private m_LastName As String
    
    	<MaxLength(25)> _
    	Public Property HomePhone() As String
    		Get
    			Return m_HomePhone
    		End Get
    		Set
    			m_HomePhone = Value
    		End Set
    	End Property
    	Private m_HomePhone As String
    
    	<MaxLength(25)> _
    	Public Property MobilePhone() As String
    		Get
    			Return m_MobilePhone
    		End Get
    		Set
    			m_MobilePhone = Value
    		End Set
    	End Property
    	Private m_MobilePhone As String
    
    	Public Overridable Property Address() As ddressType
    		Get
    			Return m_Address
    		End Get
    		Set
    			m_Address = Value
    		End Set
    	End Property
    	Private Overridable m_Address As ddressType
    
    	Public Overridable Property Orders() As ICollection(Of Order)
    		Get
    			Return m_Orders
    		End Get
    		Set
    			m_Orders = Value
    		End Set
    	End Property
    	Private Overridable m_Orders As ICollection(Of Order)
    	Public Overridable Property Company() As Company
    		Get
    			Return m_Company
    		End Get
    		Set
    			m_Company = Value
    		End Set
    	End Property
    	Private Overridable m_Company As Company
    	Public Overridable Property Companies() As ICollection(Of Company)
    		Get
    			Return m_Companies
    		End Get
    		Set
    			m_Companies = Value
    		End Set
    	End Property
    	Private Overridable m_Companies As ICollection(Of Company)
    End Class
    
    <Table("AddressType")> _
    Public Class AddressType
    
    	<Key> _
    	<DatabaseGenerated(DatabaseGeneratedOption.Identity)> _
    	Public Property Id() As Long
    		Get
    			Return m_Id
    		End Get
    		Set
    			m_Id = Value
    		End Set
    	End Property
    	Private m_Id As Long
    
    	<MaxLength(120)> _
    	Public Property AddressTitle() As String
    		Get
    			Return m_AddressTitle
    		End Get
    		Set
    			m_AddressTitle = Value
    		End Set
    	End Property
    	Private m_AddressTitle As String
    
    	<MaxLength(60)> _
    	Public Property Address() As String
    		Get
    			Return m_Address
    		End Get
    		Set
    			m_Address = Value
    		End Set
    	End Property
    	Private m_Address As String
    
    	<MaxLength(30)> _
    	Public Property City() As String
    		Get
    			Return m_City
    		End Get
    		Set
    			m_City = Value
    		End Set
    	End Property
    	Private m_City As String
    
    	<MaxLength(20)> _
    	Public Property Region() As String
    		Get
    			Return m_Region
    		End Get
    		Set
    			m_Region = Value
    		End Set
    	End Property
    	Private m_Region As String
    
    	<MaxLength(15)> _
    	Public Property PostalCode() As String
    		Get
    			Return m_PostalCode
    		End Get
    		Set
    			m_PostalCode = Value
    		End Set
    	End Property
    	Private m_PostalCode As String
    
    	<MaxLength(20)> _
    	Public Property Country() As String
    		Get
    			Return m_Country
    		End Get
    		Set
    			m_Country = Value
    		End Set
    	End Property
    	Private m_Country As String
    
    	<MaxLength(25)> _
    	Public Property Phone() As String
    		Get
    			Return m_Phone
    		End Get
    		Set
    			m_Phone = Value
    		End Set
    	End Property
    	Private m_Phone As String
    
    	<MaxLength(25)> _
    	Public Property Fax() As String
    		Get
    			Return m_Fax
    		End Get
    		Set
    			m_Fax = Value
    		End Set
    	End Property
    	Private m_Fax As String
    End Class
    
  8. Add our classes to the DbContext descendant as DbSet properties. If necessary, you can also write fluent mapping, by overriding the OnModelCreating method.

    [C#]
    public class MyDbContext : DbContext {
     
      protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
     
        optionsBuilder.UseSQLite(@"DataSource=mydatabase.db;");
      }
     
      protected override void OnModelCreating(ModelBuilder modelBuilder) {
     
        modelBuilder.Entity<OrderDetail>()
          .HasKey(p => new { p.OrderID, p.ProductID });
      } 
      
      public DbSet<Product> Products { get; set; }
      public DbSet<ProductCategory> ProductCategories { get; set; }
      public DbSet<OrderDetail> OrderDetails { get; set; }
      public DbSet<Order> Orders { get; set; }
      public DbSet<Company> Companies { get; set; }
      public DbSet<PersonContact> PersonContacts { get; set; }
    }
    [Visual Basic]
    Public Class MyDbContext
    	Inherits DbContext
    
    	Protected Overrides Sub OnConfiguring(optionsBuilder As DbContextOptionsBuilder)
    
    		optionsBuilder.UseSQLite("DataSource=mydatabase.db;")
    	End Sub
    
    	Protected Overrides Sub OnModelCreating(modelBuilder As ModelBuilder)
    
    		modelBuilder.Entity(Of OrderDetail)().HasKey(Function(p) New From { _
    			p.OrderID, _
    			p.ProductID _
    		})
    	End Sub
    
    	Public Property Products() As DbSet(Of Product)
    		Get
    			Return m_Products
    		End Get
    		Set
    			m_Products = Value
    		End Set
    	End Property
    	Private m_Products As DbSet(Of Product)
    	Public Property ProductCategories() As DbSet(Of ProductCategory)
    		Get
    			Return m_ProductCategories
    		End Get
    		Set
    			m_ProductCategories = Value
    		End Set
    	End Property
    	Private m_ProductCategories As DbSet(Of ProductCategory)
    	Public Property OrderDetails() As DbSet(Of OrderDetail)
    		Get
    			Return m_OrderDetails
    		End Get
    		Set
    			m_OrderDetails = Value
    		End Set
    	End Property
    	Private m_OrderDetails As DbSet(Of OrderDetail)
    	Public Property Orders() As DbSet(Of Order)
    		Get
    			Return m_Orders
    		End Get
    		Set
    			m_Orders = Value
    		End Set
    	End Property
    	Private m_Orders As DbSet(Of Order)
    	Public Property Companies() As DbSet(Of Company)
    		Get
    			Return m_Companies
    		End Get
    		Set
    			m_Companies = Value
    		End Set
    	End Property
    	Private m_Companies As DbSet(Of Company)
    	Public Property PersonContacts() As DbSet(Of PersonContact)
    		Get
    			Return m_PersonContacts
    		End Get
    		Set
    			m_PersonContacts = Value
    		End Set
    	End Property
    	Private m_PersonContacts As DbSet(Of PersonContact)
    End Class
    
  9. Now let's choose how to create the database. We can generate Code-First Migrations. Or, for test purposes, we can implement the analogue of Entity Framework 6 initialization strategy DropCreateDatabaseAlways.

    [C#]
      public static class MyDbContextSeeder {
     
        public static void Seed(MyDbContext context) {
     
          context.Database.EnsureDeleted();
          context.Database.EnsureCreated();
     
          context.ProductCategories.Add(new ProductCategory() {
            CategoryName = "prose"
          });
          context.ProductCategories.Add(new ProductCategory() {
            CategoryName = "novel"
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "poetry",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "novel")
          });
          context.ProductCategories.Add(new ProductCategory() {
            CategoryName = "detective story"
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "fantasy",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "novel")
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "pop art",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "fantasy")
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "textbook"
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "research book",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "textbook")
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "poem",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "novel")
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "collection",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "textbook")
          });
          context.ProductCategories.Add(new ProductCategory() { 
            CategoryName = "dictionary",
            ParentCategory = context.ProductCategories.Local.Single(p => p.CategoryName == "collection")
          });
     
          context.Products.Add(new Product() { 
            ProductName = "Shakespeare W. Shakespeare's dramatische Werke",
            Price = 78,
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "prose")
          });
          context.Products.Add(new Product() { 
            ProductName = "King Stephen. 'Salem's Lot", 
            Price = 67, 
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "poetry")
          });
          context.Products.Add(new Product() { 
            ProductName = "Plutarchus. Plutarch's moralia", 
            Price = 89, 
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "prose")
          });
          context.Products.Add(new Product() { 
            ProductName = "Twain Mark. Ventures of Huckleberry Finn", 
            Price = 34, 
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "novel")
          });
          context.Products.Add(new Product() { 
            ProductName = "Harrison G. B. England in Shakespeare's day", 
            Price = 540, 
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "novel")
          });
          context.Products.Add(new Product() { 
            ProductName = "Corkett Anne. The salamander's laughter", 
            Price = 5,
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "poem")
          });
          context.Products.Add(new Product() { 
            ProductName = "Lightman Alan. Einstein''s dreams", 
            Price = 5,
            Category = context.ProductCategories.Local.Single(p => p.CategoryName == "poem")
          });
     
          context.Companies.Add(new Company() {
            CompanyName = "Borland UK CodeGear Division",
            Web = "support.codegear.com/"
          });
          context.Companies.Add(new Company() {
            CompanyName = "Alfa-Bank",
            Web = "www.alfabank.com"
          });
          context.Companies.Add(new Company() {
            CompanyName = "Pioneer Pole Buildings, Inc.",
            Web = "www.pioneerpolebuildings.com"
          });
          context.Companies.Add(new Company() {
            CompanyName = "Orion Telecoms (Pty) Ltd.",
            Web = "www.oriontele.com"
          });
          context.Companies.Add(new Company() {
            CompanyName = "Orderbase Consulting GmbH",
            Web = "orderbase.de"
          });
     
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2007, 4, 11),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Borland UK CodeGear Division")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2006, 3, 11),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Borland UK CodeGear Division")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2006, 8, 6),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Alfa-Bank")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2004, 7, 6),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Alfa-Bank")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2006, 8, 8),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Alfa-Bank")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2003, 3, 1),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Pioneer Pole Buildings, Inc.")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2005, 8, 6),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Orion Telecoms (Pty) Ltd.")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2006, 8, 1),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Orion Telecoms (Pty) Ltd.")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2007, 7, 1),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Orion Telecoms (Pty) Ltd.")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2007, 2, 6),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Orderbase Consulting GmbH")
          });
          context.Orders.Add(new Order() {
            OrderDate = new DateTime(2007, 8, 1),
            Company = context.Companies.Local.Single(c => c.CompanyName == "Orderbase Consulting GmbH")
          });
     
          context.SaveChanges();
        }
      }
    
    [Visual Basic]
    Public NotInheritable Class MyDbContextSeeder
    	Private Sub New()
    	End Sub
    
    	Public Shared Sub Seed(context As MyDbContext)
    
    		context.Database.EnsureDeleted()
    		context.Database.EnsureCreated()
    
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "prose" _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "novel" _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "poetry", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "novel") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "detective story" _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "fantasy", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "novel") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "pop art", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "fantasy") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "textbook" _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "research book", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "textbook") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "poem", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "novel") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "collection", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "textbook") _
    		})
    		context.ProductCategories.Add(New ProductCategory() With { _
    			Key .CategoryName = "dictionary", _
    			Key .ParentCategory = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "collection") _
    		})
    
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Shakespeare W. Shakespeare's dramatische Werke", _
    			Key .Price = 78, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "prose") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "King Stephen. 'Salem's Lot", _
    			Key .Price = 67, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "poetry") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Plutarchus. Plutarch's moralia", _
    			Key .Price = 89, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "prose") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Twain Mark. Ventures of Huckleberry Finn", _
    			Key .Price = 34, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "novel") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Harrison G. B. England in Shakespeare's day", _
    			Key .Price = 540, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "novel") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Corkett Anne. The salamander's laughter", _
    			Key .Price = 5, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "poem") _
    		})
    		context.Products.Add(New Product() With { _
    			Key .ProductName = "Lightman Alan. Einstein''s dreams", _
    			Key .Price = 5, _
    			Key .Category = context.ProductCategories.Local.[Single](Function(p) p.CategoryName = "poem") _
    		})
    
    		context.Companies.Add(New Company() With { _
    			Key .CompanyName = "Borland UK CodeGear Division", _
    			Key .Web = "support.codegear.com/" _
    		})
    		context.Companies.Add(New Company() With { _
    			Key .CompanyName = "Alfa-Bank", _
    			Key .Web = "www.alfabank.com" _
    		})
    		context.Companies.Add(New Company() With { _
    			Key .CompanyName = "Pioneer Pole Buildings, Inc.", _
    			Key .Web = "www.pioneerpolebuildings.com" _
    		})
    		context.Companies.Add(New Company() With { _
    			Key .CompanyName = "Orion Telecoms (Pty) Ltd.", _
    			Key .Web = "www.oriontele.com" _
    		})
    		context.Companies.Add(New Company() With { _
    			Key .CompanyName = "Orderbase Consulting GmbH", _
    			Key .Web = "orderbase.de" _
    		})
    
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2007, 4, 11), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Borland UK CodeGear Division") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2006, 3, 11), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Borland UK CodeGear Division") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2006, 8, 6), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Alfa-Bank") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2004, 7, 6), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Alfa-Bank") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2006, 8, 8), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Alfa-Bank") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2003, 3, 1), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Pioneer Pole Buildings, Inc.") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2005, 8, 6), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Orion Telecoms (Pty) Ltd.") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2006, 8, 1), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Orion Telecoms (Pty) Ltd.") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2007, 7, 1), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Orion Telecoms (Pty) Ltd.") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2007, 2, 6), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Orderbase Consulting GmbH") _
    		})
    		context.Orders.Add(New Order() With { _
    			Key .OrderDate = New DateTime(2007, 8, 1), _
    			Key .Company = context.Companies.Local.[Single](Function(c) c.CompanyName = "Orderbase Consulting GmbH") _
    		})
    
    		context.SaveChanges()
    	End Sub
    End Class
    
  10. Now let's add code that creates the context, re-creates the database, fills it with the test data, and executes LINQ to Entities queries. Before compiling the following code add the Microsoft.EntityFrameworkCore namespace to the using list (for C#) or to the Imports list (for VB).

    [C#]
      class Program {
     
        static void Main(string[] args) {
     
          var context = new MyDbContext ();
     
          Console.WriteLine("Entity Framework Core (EF7) Code-First sample");
          Console.WriteLine();
     
          MyDbContextSeeder.Seed(context);
     
          Console.WriteLine("Products with categories");
          Console.WriteLine();
     
          var query = context.Products.Include(p => p.Category)
              .Where(p => p.Price > 20.0)
              .ToList();
     
          Console.WriteLine("{0,-10} | {1,-50} | {2}", "ProductID", "ProductName", "CategoryName");
          Console.WriteLine();
          foreach (var product in query )
            Console.WriteLine("{0,-10} | {1,-50} | {2}", product.ProductID, product.ProductName, product.Category.CategoryName);
     
          Console.ReadKey();
        }
      }
    [Visual Basic]
    Class Program
    
    	Private Shared Sub Main(args As String())
    
    		Dim context = New MyDbContext()
    
    		Console.WriteLine("Entity Framework Core (EF7) Code-First sample")
    		Console.WriteLine()
    
    		MyDbContextSeeder.Seed(context)
    
    		Console.WriteLine("Products with categories")
    		Console.WriteLine()
    
    		Dim query = context.Products.Include(Function(p) p.Category).Where(Function(p) p.Price > 20.0).ToList()
    
    		Console.WriteLine("{0,-10} | {1,-50} | {2}", "ProductID", "ProductName", "CategoryName")
    		Console.WriteLine()
    		For Each product As var In query
    			Console.WriteLine("{0,-10} | {1,-50} | {2}", product.ProductID, product.ProductName, product.Category.CategoryName)
    		Next
    
    		Console.ReadKey()
    	End Sub
    End Class
    
  11. Now we can run the application. It will create tables in the database, fill them with data, execute a query and output its results to the console:

    Entity Framework Core (EF7) Code-First sample
    
    Products with categories
    
    ProductID  | ProductName                                        | CategoryName
    
    1          | Harrison G. B. England in Shakespeare's day        | novel
    2          | Twain Mark. Ventures of Huckleberry Finn           | novel
    3          | Plutarchus. Plutarch's moralia                     | prose
    4          | Shakespeare W. Shakespeare's dramatische Werke     | prose
    5          | King Stephen. 'Salem's Lot                         | poetry

Conclusion

This article shows how to create a console application, working with an SQLite database via Entity Framework Core, using dotConnect for SQLite as an Entity Framework Core provider. dotConnect for SQLite is an ADO.NET provider from Devart with support for such ORM solutions as Entity Framework v1 - v6, Entity Framework Core, NHibernate, and Devart's own ORM LinqConnect.

dotConnect for SQLite includes Entity Developer - a powerful visual ORM model designer with support for Database First, Model First, and mixed development approaches and powerful code generation.

Back to list