In this post I will explain How to create Foreign Key relationship in Entity Framework(EF).
When you create a model of relation database some time we got following error
Now I just create a Model class with out relation ship .Now I will explain How to set ForeighKeyAttribute of above model class bellow.In Above table student and Course table have only primary key.But Course Selection table have Foreign key studentId and CourseId so we rewrite Course Selection class to bellow format
When you create a model of relation database some time we got following error
Unable to retrieve association information for
association 'Models.Product_Parent'. Only models that include foreign key
information are supported. See Entity Framework documentation for details on
creating models that include foreign key information.
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I will explain how to create Model class for following relation data base
public class Student
{
[Key]
public int StudentId { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
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public class CourseSelection
{
[Key]
public int CourseSelectionID { get; set; }
public string CourseID { get; set; }
public int StudentID { get; set; }
}
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public class Course
{
[Key]
public string CourseID { get; set; }
public String CourseName { get; set; }
}
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public class CourseSelection
{
[Key]
public int CourseSelectionID { get; set; }
ForeignKey("Course ")]
public string CourseID { get; set; }
public virtual Cource course { get; set; }
[ForeignKey("Student
")]
public
int StudentID { get; set; }
public virtual Student Student { get; set;
}
}
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public virtual Student course { get; set; } ?
ReplyDeleteor
public virtual Course course { get; set; } ?
yes this is public virtual Course course { get; set; }
ReplyDeleteExcellent example but fix:
ReplyDeletepublic virtual Student course { get; set; } to public virtual Course course { get; set; }
That is the correct form.