This tutorial guides you through the process of creating a simple application powered by Entity Framework Core designer you can use either. This application will create tables in the database based on the model in run-time, fill them with sample data, and execute queries.
If you want to target Entity Framework Core 2.2, this tutorial requires the following:
This article uses classes from dotConnect for SQLite, a high-performance ADO.NET provider with the ORM support (Entity Framework, NHibernate, and LinqConnect).
If you want to target Entity Framework Core 3.1, this tutorial requires the following:
If you want to target Entity Framework Core 2.2, this tutorial requires the following:
If you want to target Entity Framework Core 1.1, this tutorial requires the following:
Note that Entity Framework support is available only in Professional Edition of dotConnect for SQLite.
To create the sample application, let's perform the following steps:
Install-Package Microsoft.EntityFrameworkCore.Relational
Additionally you need to add references to the following assemblies to your project:
Please note that there are three versions of Devart.Data.Oracle.Entity.EFCore.dll assemblies for different Entity Framework Core versions - 1.1, 2.2, and 3.1. They are located respectively in \Entity\EFCore, \Entity\EFCore2, and \Entity\EFCore3 subfolders of the [!ProductName] installation folder.
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
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
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; }
}
<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
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
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();
}
}
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
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
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
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.
We use cookies to provide you with a better experience on the Devart website. You can read more about our use of cookies in our Cookies Policy.
Click OK to continue browsing the Devart site. Be aware you can disable cookies at any time.