Musical store MVC Mapping RSS

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  smanjula

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  Musical store MVC Mapping

  May 31, 2011 09:23 AM|LINK

  Hai,

            In Musical Store,MVC ,I have created tables and  created Entity data model.But i got this error.I cant Understand this error.Pls help me to solve this issue.

  The type 'MvcApplication1.Models.album' was not mapped. Check that the type has not been explicitly excluded by using the Ignore method or NotMappedAttribute data annotation. Verify that the type was defined as a class, is not primitive, nested or generic, and does not inherit from EntityObject.
  

  • Moved by XIII on May 31, 2011 09:25 AM
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  Decker Dong ...

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  Re: Musical store MVC Mapping

  Jun 02, 2011 02:05 AM|LINK

  Hello again：）
  
  How did you do with that?

  Please tell us in details step by step of your creating EF models.

  with your screen is well welcomed.

  Thx

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  smanjula

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  Re: Musical store MVC Mapping

  Jun 02, 2011 04:04 AM|LINK

  sample

  • Edited by smanjula on Jun 02, 2011 04:28 AM
  • Edited by smanjula on Jun 02, 2011 04:44 AM
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  smanjula

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  Re: Musical store MVC Mapping

  Jun 02, 2011 04:43 AM|LINK

  Hai,

              First I created a database by right clicking on the App_Data Folder.

               Next  i created 3 tables(enrollment,student,course)

              Next i created Model.Edmx by right clicking on the Models Folder.

              Then i created school context.cs file.

  public class schoolcontext:DbContext
      {     
          public DbSet<student> student { get; set; }
          public DbSet<Enrollments> enrollment { get; set; }
          public DbSet<course> course { get;set; }
   
          protected override void OnModelCreating(DbModelBuilder modelBuilder)
          {
              base.OnModelCreating(modelBuilder);
          }
  
  Then i initialized the values for the database in the cs file.
  for table Student
  
  

    public partial class student
      {
          public int StudentID { get; set; }
          public string Lastname { get; set; }
          public string FirstmidName { get; set; }
          public DateTime Enrollmentdate { get; set; }
          public virtual ICollection<Enrollments> Enrollments { get; set; }
   
      }
  
  For class Course

  public class course
      {
          public int Courseid { get; set; }
          public string title { get; set; }
          public int credits { get; set; }
          public int EnrollmentId { get; set; }
          public virtual ICollection<Enrollments> Enrollment { get; set; }
      }

   

  for class Enrollment.

   public partial class Enrollments
      {   
          public int EnrollmentId { get; set; }       
          public int Courseid { get; set; }
          public int studentid { get; set; }
          public decimal? Grade { get; set; }
          public virtual student student { get; set; }
          public virtual course course { get; set; }
      }
  
  These are the steps i have done.
  
  But i got the error:
  
  'Unable to retrieve Metadata for mvc2.models.student'.One or more validation errors were detected during model generation.
  System.Data.Edm.EdmEntitytype:Entity type:'Enrollments' has no key defined.Define the key for this entity type.
  
  System.

  Data.Edm.EdmEntitytype:Entityset:enrollment is based on type Enrollments that has no keys defined.
  I followed the tutorial:http://www.asp.net/entity-framework/tutorials/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application
  
  Pls help me in this issue.I was new to MVC.Thanks on advance

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  Decker Dong ...

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  Re: Musical store MVC Mapping

  Jun 02, 2011 05:11 AM|LINK

  Hello again：）
  
  1）Please confirm that your "courseid" is really fitting what you've defined in the db, pay attention to spelling worng or case sensitive...

  2) If still fails, please——

  1. Include the following namespace: using System.ComponentModel.DataAnnotations;

  2. Add attribute [key] to define which is your primary key.

  Thx again.

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  smanjula

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  349 Posts

  Re: Musical store MVC Mapping

  Jun 02, 2011 05:20 AM|LINK

  Hai,

                   In student Table i have the columns,

                   sid(primary key),Lastname.firstmidname,enrollmentdate

                  In course table i have the columns,

                  cid(primary key),title,credits,enrollmentid

                 In enrollment table i have the columns,

                courseid,studentid,grade.

                 In student.cs file i have,

  public partial class student
      {
         
          public int StudentID { get; set; }
          public string LastName { get; set; }
          public string FirstMidName { get; set; }
          public DateTime EnrollmentDate { get; set; }
          public virtual ICollection<Enrollments> Enrollments { get; set; }
   
      }
  
  as u said i have changed this as

  using System.ComponentModel.DataAnnotations;
   
  namespace mvc2.Models
  {
      public partial class student
      {
         [Key]
          public int StudentID { get; set; }
          public string LastName { get; set; }
          public string FirstMidName { get; set; }
          public DateTime EnrollmentDate { get; set; }
          public virtual ICollection<Enrollments> Enrollments { get; set; }
   
      }
  
  in course.cs
  
  

   public class course
      {
          public int Courseid { get; set; }
          public string title { get; set; }
          public int credits { get; set; }
          public int EnrollmentId { get; set; }
          public virtual ICollection<Enrollments> Enrollment { get; set; }
      }
  
  in enrollment.cs 

   public partial class Enrollments
      {   
          public int EnrollmentId { get; set; }       
          public int Courseid { get; set; }
          public int studentid { get; set; }
          public decimal? Grade { get; set; }
          public virtual student student { get; set; }
          public virtual course course { get; set; }
      }
  
  even i done the chage i still get the error,Can u pls tell me the steps to be followed.I do know what is the mistake i done.I will be thankful to u if this issue is solved.

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  Decker Dong ...

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  Re: Musical store MVC Mapping

  Jun 02, 2011 05:28 AM|LINK

  Please make sure that your every table's primary key should match with what you've defined in them——
  You can try to change like this:
  
  For Student table：
  
  StudentID(primary key),……
  
  For Course table：
  Courseid(primary key），……
  
  For enrollment table：
  Please add a column as a primary key——
  EnrollmentId(primary key)
  
  And then remove all the"[Key]" and have a try.

  • Edited by decker dong - msft on Jun 02, 2011 05:28 AM
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  smanjula

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  349 Posts

  Re: Musical store MVC Mapping

  Jun 02, 2011 05:37 AM|LINK

  I have changed as u said.Still the error continues.

  Can u pls explain the steps to be followed clearly to display datas from database in mvc.

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  Decker Dong ...

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  Re: Musical store MVC Mapping

  Jun 02, 2011 05:46 AM|LINK

  Hello again：）
  
  I'll do a demo and have a try. And I'll tell you later about my result.

  Would you mind leaving your mailbox so as to let me send you my codes?

  Thx 

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  smanjula

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  349 Posts

  Re: Musical store MVC Mapping

  Jun 02, 2011 06:36 AM|LINK

  hai,

                  My Mail id is:2010smanjula@gmail.com.