HibernatingRhinos.Profiler.Appender.EntityFramework.EntityFrameworkProfiler.Initialize();

using System.Collections.Generic;

namespace EF_Sample06.Models
{
    public class Department
    {
        public int DepartmentId { get; set; }
        public string Name { get; set; }

        //Creates Employee navigation property for Lazy Loading (1:many)
        public virtual ICollection<Employee> Employees { get; set; }
    }
}

namespace EF_Sample06.Models
{
    public class Employee
    {
        public int EmployeeId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }        

        //Creates Department navigation property for Lazy Loading
        public virtual Department Department { get; set; }
    }
}

using System.Data.Entity;
using EF_Sample06.Models;

namespace EF_Sample06.DataLayer
{
    public class Sample06Context : DbContext
    {
        public DbSet<Department> Departments { set; get; }
        public DbSet<Employee> Employees { set; get; }
    }
}

using System.Collections.Generic;
using System.Data.Entity.Migrations;
using EF_Sample06.Models;

namespace EF_Sample06.DataLayer
{
    public class Configuration : DbMigrationsConfiguration<Sample06Context>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
            AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(Sample06Context context)
        {
            var employee1 = new Employee { FirstName = "f name1", LastName = "l name1" };
            var employee2 = new Employee { FirstName = "f name2", LastName = "l name2" };
            var employee3 = new Employee { FirstName = "f name3", LastName = "l name3" };
            var employee4 = new Employee { FirstName = "f name4", LastName = "l name4" };

            var dept1 = new Department { Name = "dept 1", Employees = new List<Employee> { employee1, employee2 } };
            var dept2 = new Department { Name = "dept 2", Employees = new List<Employee> { employee3 } };
            var dept3 = new Department { Name = "dept 3", Employees = new List<Employee> { employee4 } };

            context.Departments.Add(dept1);
            context.Departments.Add(dept2);
            context.Departments.Add(dept3);
            base.Seed(context);
        }
    }
}

void ExportMappings(DbContext context, string edmxFile)
{
     var settings = new XmlWriterSettings { Indent = true };
     using (XmlWriter writer = XmlWriter.Create(edmxFile, settings))
     {
         System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(context, writer);
     }
}

using (var db = new Sample06Context())
{
     ExportMappings(db, "mappings.edmx");
}

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using EF_Sample06.DataLayer;
using EF_Sample06.Models;

namespace EF_Sample06
{
    class Program
    {
        static IList<Employee> FindEmployees(string fName, string lName, bool byName, bool byLName)
        { 
            using (var db = new Sample06Context())
            {
                IQueryable<Employee> query = db.Employees.AsQueryable();

                if (byLName)
                {
                    query = query.Where(x => x.LastName == lName);
                }

                if (byName)
                {
                    query = query.Where(x => x.FirstName == fName);
                }

                return query.ToList();
            }
        }

        static void Main(string[] args)
        {
            // note: remove this line if you received : create database is not supported by this provider.
            HibernatingRhinos.Profiler.Appender.EntityFramework.EntityFrameworkProfiler.Initialize();

            Database.SetInitializer(new MigrateDatabaseToLatestVersion<Sample06Context, Configuration>());

            var list = FindEmployees("f name1", "l name1", true, true);
            foreach (var item in list)
            {
                Console.WriteLine(item.FirstName);
            }
        }
    }
}

var list = FindEmployees("f name1", "l name1", true, true);

SELECT [Extent1].[EmployeeId]              AS [EmployeeId],
       [Extent1].[FirstName]               AS [FirstName],
       [Extent1].[LastName]                AS [LastName],
       [Extent1].[Department_DepartmentId] AS [Department_DepartmentId]
FROM   [dbo].[Employees] AS [Extent1]
WHERE  ([Extent1].[LastName] = 'l name1' /* @p__linq__0 */)
       AND ([Extent1].[FirstName] = 'f name1' /* @p__linq__1 */)

using (var db = new Sample06Context())
{
    var dept1 = db.Departments.Find(1);
    if (dept1 != null)
    {
        Console.WriteLine(dept1.Name);
        foreach (var item in dept1.Employees)
        {
             Console.WriteLine(item.FirstName);
        }
    }
}

SELECT [Limit1].[DepartmentId] AS [DepartmentId],
       [Limit1].[Name]         AS [Name]
FROM   (SELECT TOP (2) [Extent1].[DepartmentId] AS [DepartmentId],
                       [Extent1].[Name]         AS [Name]
        FROM   [dbo].[Departments] AS [Extent1]
        WHERE  [Extent1].[DepartmentId] = 1 /* @p0 */) AS [Limit1]


SELECT [Extent1].[EmployeeId]              AS [EmployeeId],
       [Extent1].[FirstName]               AS [FirstName],
       [Extent1].[LastName]                AS [LastName],
       [Extent1].[Department_DepartmentId] AS [Department_DepartmentId]
FROM   [dbo].[Employees] AS [Extent1]
WHERE  ([Extent1].[Department_DepartmentId] IS NOT NULL)
       AND ([Extent1].[Department_DepartmentId] = 1 /* @EntityKeyValue1 */)

using (var db = new Sample06Context())
{
      foreach (var dept in db.Departments)
      {
           Console.WriteLine(dept.Name);
           foreach (var item in dept.Employees)
           {
                Console.WriteLine(item.FirstName);
            }
        }
}

There is already an open DataReader associated with this Command which must be closed first

<connectionStrings>
    <clear/>
    <add
       name="Sample06Context"
       connectionString="Data Source=(local);Initial Catalog=testdb2012;Integrated Security = true;MultipleActiveResultSets=True;"
       providerName="System.Data.SqlClient"
      />
</connectionStrings>

using (var db = new Sample06Context())
{
      foreach (var dept in db.Departments.Include(x => x.Employees))
      {
           Console.WriteLine(dept.Name);
           foreach (var item in dept.Employees)
           {
              Console.WriteLine(item.FirstName);
           }
       }
}

SELECT [Project1].[DepartmentId]            AS [DepartmentId],
       [Project1].[Name]                    AS [Name],
       [Project1].[C1]                      AS [C1],
       [Project1].[EmployeeId]              AS [EmployeeId],
       [Project1].[FirstName]               AS [FirstName],
       [Project1].[LastName]                AS [LastName],
       [Project1].[Department_DepartmentId] AS [Department_DepartmentId]
FROM   (SELECT [Extent1].[DepartmentId]            AS [DepartmentId],
               [Extent1].[Name]                    AS [Name],
               [Extent2].[EmployeeId]              AS [EmployeeId],
               [Extent2].[FirstName]               AS [FirstName],
               [Extent2].[LastName]                AS [LastName],
               [Extent2].[Department_DepartmentId] AS [Department_DepartmentId],
               CASE
                 WHEN ([Extent2].[EmployeeId] IS NULL) THEN CAST(NULL AS int)
                 ELSE 1
               END                                 AS [C1]
        FROM   [dbo].[Departments] AS [Extent1]
               LEFT OUTER JOIN [dbo].[Employees] AS [Extent2]
                 ON [Extent1].[DepartmentId] = [Extent2].[Department_DepartmentId]) AS [Project1]
ORDER  BY [Project1].[DepartmentId] ASC,
          [Project1].[C1] ASC

public class Sample06Context : DbContext
{
        public Sample06Context()
        {
            this.Configuration.LazyLoadingEnabled = false;
        }

public class Department
{
     public int DepartmentId { get; set; }
     public string Name { get; set; }

     public  ICollection<Employee> Employees { get; set; }
     public Department()
     {
         Employees = new HashSet<Employee>();
     }
}

public class Account
{
       public virtual int Id { get; set; }

       [NotNullNotEmpty]
       [Length(Min = 3, Max = 120, Message = "طول نام باید بین 3 و 120 کاراکتر باشد")]
       public virtual string Name { get; set; } 
}

public class Category
{
       public virtual int Id { get; set; }

       [NotNullNotEmpty]
       [Length(Min = 3, Max = 130, Message = "طول نام باید بین 3 و 130 کاراکتر باشد")]
       public virtual string Name { get; set; } 
}

public class Payee
{
       public virtual int Id { get; set; }

       [NotNullNotEmpty]
       [Length(Min = 3, Max = 120, Message = "طول نام باید بین 3 و 120 کاراکتر باشد")]
       public virtual string Name { get; set; }
}

public class Bill
{
       public virtual int Id { get; set; }

       [NotNull]
       public virtual Account Account { get; set; }

       [NotNull]
       public virtual Category Category { get; set; }

       [NotNull]
       public virtual Payee Payee { get; set; }

       [NotNull]
       public virtual decimal Amount { set; get; }

       [NotNull]
       public virtual DateTime BillDate { set; get; }

       [NotNullNotEmpty]
       [Length(Min = 1, Max = 500, Message = "طول توضیحات باید بین 1 و 500 کاراکتر باشد")]
       public virtual string Description { get; set; } 
}

    create table Accounts (
       AccountId INT IDENTITY NOT NULL,
      Name NVARCHAR(120) not null,
      primary key (AccountId)
   )

   create table Bills (
       BillId INT IDENTITY NOT NULL,
      Amount DECIMAL(19,5) not null,
      BillDate DATETIME not null,
      Description NVARCHAR(500) not null,
      AccountId INT not null,
      CategoryId INT not null,
      PayeeId INT not null,
      primary key (BillId)
   )

   create table Categories (
       CategoryId INT IDENTITY NOT NULL,
      Name NVARCHAR(130) not null,
      primary key (CategoryId)
   )

   create table Payees (
       PayeeId INT IDENTITY NOT NULL,
      Name NVARCHAR(120) not null,
      primary key (PayeeId)
   )

   alter table Bills
       add constraint fk_Account_Bill
       foreign key (AccountId)
       references Accounts

   alter table Bills
       add constraint fk_Category_Bill
       foreign key (CategoryId)
       references Categories

   alter table Bills
       add constraint fk_Payee_Bill
       foreign key (PayeeId)
       references Payees

var newBill = new Bill
                   {
                       Account = accountRepository.GetByKey(1),
                       Amount = 1,
                       BillDate = DateTime.Now,
                       Category = categoryRepository.GetByKey(1),
                       Description = "testestest...",
                       Payee = payeeRepository.GetByKey(1)
                   };

SELECT account0_.AccountId as AccountId0_0_, account0_.Name as Name0_0_
FROM Accounts account0_ WHERE account0_.AccountId=@p0;@p0 = 1 [Type: Int32 (0)]

SELECT category0_.CategoryId as CategoryId2_0_, category0_.Name as Name2_0_
FROM Categories category0_ WHERE category0_.CategoryId=@p0;@p0 = 1 [Type: Int32 (0)]

SELECT payee0_.PayeeId as PayeeId3_0_, payee0_.Name as Name3_0_
FROM Payees payee0_ WHERE payee0_.PayeeId=@p0;@p0 = 1 [Type: Int32 (0)]

INSERT INTO Bills (Amount, BillDate, Description, AccountId, CategoryId, PayeeId)
VALUES (@p0, @p1, @p2, @p3, @p4, @p5);
select SCOPE_IDENTITY();
@p0 = 1 [Type: Decimal (0)],
@p1 = 2010/12/27 11:48:33 ق.ظ [Type: DateTime (0)],
@p2 = 'testestest...' [Type: String (500)],
@p3 = 1 [Type: Int32 (0)],
@p4 = 1 [Type: Int32 (0)],
@p5 = 1 [Type: Int32 (0)]

INSERT INTO Bills (Amount, BillDate, Description, AccountId, CategoryId, PayeeId)
VALUES (@p0, @p1, @p2, @p3, @p4, @p5);
select SCOPE_IDENTITY();
@p0 = 1 [Type: Decimal (0)],
@p1 = 2010/12/27 11:58:22 ق.ظ [Type: DateTime (0)],
@p2 = 'testestest...' [Type: String (500)],
@p3 = 1 [Type: Int32 (0)],
@p4 = 1 [Type: Int32 (0)],
@p5 = 1 [Type: Int32 (0)]

public partial class Bill : EntityObject
{
       public global::System.Int32 BillId {set;get;}
       public global::System.Decimal Amount {set;get;}
       public global::System.DateTime BillDate {set;get;}
       public global::System.String Description {set;get;}
       public global::System.Int32 AccountId {set;get;}
       public global::System.Int32 CategoryId {set;get;}
       public global::System.Int32 PayeeId {set;get;}
       public Account Account {set;get;}
       public Category Category {set;get;}
}

SELECT EMPLOYEEKEY,FIRSTNAME,LASTNAME, MIDDLENAME,TITLE,HIREDATE, BIRTHDATE,EMAILADDRESS,PHONE,GENDER FROM DBO.DIMEMPLOYEE WHERE DEPARTMENTNAME=@DEPARTMENTNAME AND GENDER=@GENDER