Linq: Relationship Code Sample

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Introduction

This sample shows how to implement Relationship Using LINQ in C# and ASP.NET for a beginner.

How To Do

1. Create an ASP.NET Web application using C# in Visual Studio 2008.

   File-> New -> Project -> ASP.NET Web Application

   

   

2. Add a database file to app_data - "student.mdf".
   1. Right Click App_Data, Add->New Item->Data->SQL Server DataBase.
   2. Give name Student.mdf.

      

   3. Go to the Server Explore, Expand Student DataBase, In Tables, Add New Table
   4. Add two tables, Student and Mark.

      Table: StudentColumns: StudentID int, Name nvarchar(50), Age int

      Table: Mark
      Columns: StudentID int, Class nvarchar(50), Mark int

      Add some sample data for the Student and Mark tables, (student id should be same in Mark and Student table)

      For that, right click the table and click show table data, you can add data here.

      

3. LINQ to SQL

   Right click the solution, add New Item->Data-> Linq to SQL Class.

4. Give Name "LinqToStudents.dbml".

   

5. Pick SQL Server explore, drag the two tables to the window:

   

   Save the Project.

6. Drag a DataGrid view to the Default.aspx Page:

   

7. Use the below code snippets pageload of the project:

   LinqToStudentsDataContext linqStud = new LinqToStudentsDataContext();
   var query = from s in linqStud.Students
   join h in linqStud.Marks on s.StudentID equals h.StudentID 
   select new {h.StudentID ,s.Name, };      

   GridView1.DataSource = query; 
   GridView1.DataBind(); 

   

Run the project by pressing F5.

History

• Release 1