Dt1nh6: 1 revision imported

2016-05-09T13:27:16Z

1 revision imported

Macrop at 07:32, 15 June 2015

2015-06-15T07:32:15Z

New page

[[Category:MVC]]
[[Category:CSharp]]
[[Category:Entity Framework]]
[[Category:Database]]
[[Category:SQL]]

<pre style="width:80%; border: 2px solid red; font-weight:bold;">
♠ if you don't use data in startup page you can't see data tables as created. (it took 6 hours)
</pre>

<pre style="width:80%; border: 2px solid red; font-weight:bold;">
♠ Code First includes derived classes even if only base class is defined as DbSet property.
♠ (you don't need to add them to dbset if you create them with foreign keys)
</pre>

<pre style="width:80%; border: 2px solid red; font-weight:bold;">
♠ The default convention for primary key is that Code First would create a primary key
♠ for a property if the property name is Id or <class name>Id (NOT case sensitive).
</pre>

Install-Package EntityFramework -Pre -Version 6.0.0

in '''Model''' Folder Create '''Student.cs''' class

using System;
using System.Collections.Generic;
namespace ContosoUniversity.Models
{
public class Student
{
public int ID { get; set; }
public string LastName { get; set; }
public string FirstMidName { get; set; }
public DateTime EnrollmentDate { get; set; }
public virtual ICollection<Enrollment> Enrollments { get; set; }
}
}

in '''Model''' Folder Create '''Enrollment.cs''' class

namespace ContosoUniversity.Models
{
public enum Grade
{
A, B, C, D, F
}

public class Enrollment
{
public int EnrollmentID { get; set; }
public int CourseID { get; set; }
public int StudentID { get; set; }
public Grade? Grade { get; set; }
public virtual Course Course { get; set; }
public virtual Student Student { get; set; }
}
}

in '''Model''' Folder Create '''Course.cs''' class

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;

namespace ContosoUniversity.Models
{
public class Course
{
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int CourseID { get; set; }
public string Title { get; set; }
public int Credits { get; set; }
public virtual ICollection<Enrollment> Enrollments { get; set; }
}
}

Create a folder in root as '''DAL'''
Create '''BackOfficeContext.cs''' file in '''DAL'''

using ContosoUniversity.Models;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;

namespace ContosoUniversity.DAL
{
public class SchoolContext : DbContext
{
public SchoolContext() : base("SchoolContext") {
}
public DbSet<Student> Students { get; set; }
public DbSet<Enrollment> Enrollments { get; set; }
public DbSet<Course> Courses { get; set; }

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
}

Create a file named '''BackOfficeInitializer.cs''' in '''DAL''' folder

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using ContosoUniversity.Models;

namespace ContosoUniversity.DAL
{
public class SchoolInitializer : System.Data.Entity. DropCreateDatabaseIfModelChanges<SchoolContext>
{
protected override void Seed(SchoolContext context)
{
var students = new List<Student>
{

//---------------------------------------------------------------------------------------------------------
// I think the correct syntax is this one below (ALI)
//---------------------------------------------------------------------------------------------------------
<b style="color:red;">new Student{) {FirstMidName="Carson",LastName="Alexander",EnrollmentDate=DateTime.Pa rse("2005-09-01")},</b>
//---------------------------------------------------------------------------------------------------------

new Student{FirstMidName="Carson",LastName="Alexander",EnrollmentDate=DateTime.Pa rse("2005-09-01")},
new Student{FirstMidName="Meredith",LastName="Alonso",EnrollmentDate=DateTime.Par se("2002-09-01")},
new Student{FirstMidName="Arturo",LastName="Anand",EnrollmentDate=DateTime.Parse( "2003-09-01")},
new Student{FirstMidName="Gytis",LastName="Barzdukas",EnrollmentDate=DateTime.Par se("2002-09-01")},
new Student{FirstMidName="Yan",LastName="Li",EnrollmentDate=DateTime.Parse("2002- 09-01")},
new Student{FirstMidName="Peggy",LastName="Justice",EnrollmentDate=DateTime.Parse ("2001-09-01")},
new Student{FirstMidName="Laura",LastName="Norman",EnrollmentDate=DateTime.Parse( "2003-09-01")},
new Student{FirstMidName="Nino",LastName="Olivetto",EnrollmentDate=DateTime.Parse ("2005-09-01")}
};
students.ForEach(s => context.Students.Add(s));
context.SaveChanges();

var courses = new List<Course>
{
new Course{CourseID=1050,Title="Chemistry",Credits=3,},
new Course{CourseID=4022,Title="Microeconomics",Credits=3,},
new Course{CourseID=4041,Title="Macroeconomics",Credits=3,},
new Course{CourseID=1045,Title="Calculus",Credits=4,},
new Course{CourseID=3141,Title="Trigonometry",Credits=4,},
new Course{CourseID=2021,Title="Composition",Credits=3,},
new Course{CourseID=2042,Title="Literature",Credits=4,}
};
courses.ForEach(s => context.Courses.Add(s));
context.SaveChanges();

var enrollments = new List<Enrollment>
{
new Enrollment{StudentID=1,CourseID=1050,Grade=Grade.A},
new Enrollment{StudentID=1,CourseID=4022,Grade=Grade.C},
new Enrollment{StudentID=1,CourseID=4041,Grade=Grade.B},
new Enrollment{StudentID=2,CourseID=1045,Grade=Grade.B},
new Enrollment{StudentID=2,CourseID=3141,Grade=Grade.F},
new Enrollment{StudentID=2,CourseID=2021,Grade=Grade.F},
new Enrollment{StudentID=3,CourseID=1050},
new Enrollment{StudentID=4,CourseID=1050,},
new Enrollment{StudentID=4,CourseID=4022,Grade=Grade.F},
new Enrollment{StudentID=5,CourseID=4041,Grade=Grade.C},
new Enrollment{StudentID=6,CourseID=1045},
new Enrollment{StudentID=7,CourseID=3141,Grade=Grade.A},
};
enrollments.ForEach(s => context.Enrollments.Add(s));
context.SaveChanges();
}
}
}

in '''Web.Config''' file...
<entityFramework>
<contexts>
<context type="ContosoUniversity.DAL.SchoolContext, ContosoUniversity">
<databaseInitializer type="ContosoUniversity.DAL.SchoolInitializer, ContosoUniversity" />
</context>
</contexts>

<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>

And Again in '''web.config''' file

<connectionStrings>
<add name="SchoolContext" connectionString="AttachDBFilename=|DataDirectory|\ContosoUniversity1.mdf;Data Source=(LocalDb)\v11.0;Initial Catalog=ContosoUniversity1;Integrated Security=SSPI;" providerName="System.Data.SqlClient"/>
</connectionStrings>

<appSettings>
<add key="webpages:Version" value="3.0.0.0" />
<add key="webpages:Enabled" value="false" />
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>

== The model backing the context has changed since the database was created Problem ==
in Global.asax
using System.Data.Entity;
using LogicBO.DAL;
using LogicBO.Models;
......
protected void Application_Start()
{
Database.SetInitializer<BoContext>(new DropCreateDatabaseIfModelChanges<BoContext>());

== The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties ==
.Where(q => DbFunctions.TruncateTime(q.DateStart) >= DateTime.Now.Date)

← Older revision	Revision as of 13:27, 9 May 2016
(No difference)

Code First Approach - Revision history

Dt1nh6: 1 revision imported

Macrop at 07:32, 15 June 2015