ASP.Net, ASP.Net MVC, C#, EntityFramework

EntityFramework in C# – Part1 : Welcome To EF

Entity Framework (EF) is an object-relational mapper that enables .NET developers to work with relational data using domain-specific objects. It eliminates the need for most of the data-access code that developers usually need to write.

I am gonna write an article on EF with an easy approach and i am trying to clearly show a CRUD application with EF .

For this example , I used one DB Table for simplicity . My DB is like below :::

Welcome to EntityFramework

Welcome to EntityFramework

To make the app simple , I took a ASP.Net Form Application which has a UI like below :::

Welcome to EntityFramework ASP.Net C# Web

The Markup code for my UI is like below :::

<h2>
        Welcome to EntityFramework!
    </h2>
  

  <table>
   <tr>
    <td>    
       Name
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="txtName" runat="server"></asp:TextBox>
    </td>
   </tr>
  

    <tr>
    <td>    
       Address
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="txtAddress" runat="server"></asp:TextBox>
    </td>
   </tr>

    <tr>
    <td>    
       Salary
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="txtSalary" runat="server"></asp:TextBox>
    </td>
   </tr>

     <tr>
    <td>    
   
    </td>  
    <td></td>
   
    <td>
        <asp:Button ID="Button1" runat="server" Text="Save" onclick="Button1_Click" />
    </td>
   </tr>

  </table>

  <br />
       <asp:GridView ID="employeeGrid" runat="server">
    </asp:GridView>

<h1>Delete One Row By Id</h1>

  <table>
   <tr>
    <td>    
       Put Delete Id
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="txtDeleteId" runat="server"></asp:TextBox>
    </td>
    <td>
       <asp:Button ID="btnDelete" runat="server" Text="Delete"
            onclick="btnDelete_Click"  />
    </td>
   </tr>
  </table>

   <h1>Update Value By Id</h1>

  <table>
   <tr>
    <td>    
       Put Update Id
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="TxtUpdateId" runat="server"></asp:TextBox>
    </td>

     <td>    
       Put New Address
    </td>  
    <td>
    :
    </td>
    <td>
        <asp:TextBox ID="txtUpdateAddress" runat="server"></asp:TextBox>
    </td>

    <td>
       <asp:Button ID="btnUpdate" runat="server" Text="Update" onclick="btnUpdate_Click"
             />
    </td>
   </tr>
  </table>

I have Three buttons for CREATE , UPDATE , DELETE and have a method for READ .

Lets see CREATE first .

protected void btnSave_Click(object sender, EventArgs e)
        {
            ImportantDBEntities dbEntities = new ImportantDBEntities();            
            EF_Employee employee = new EF_Employee();
            employee.Name = txtName.Text;
            employee.Address = txtAddress.Text;
            employee.Salary = Convert.ToDecimal(txtSalary.Text) ;

            dbEntities.EF_Employee.AddObject(employee);
            dbEntities.SaveChanges();

            FillEmployeeGrid();
        }

Here ImportantDBEntities is my SQL Server DB Context as you saw the DB image that my DB name is ImportantDB.

And That FillEmployeeGrid() method is my READ method which will pull the data from DB table .

private void FillEmployeeGrid()
        {
            ImportantDBEntities dbEntities = new ImportantDBEntities();

            if (dbEntities.EF_Employee != null)
            {
                var employees = dbEntities.EF_Employee;
                employeeGrid.DataSource = employees;
                employeeGrid.DataBind();
            }
        }

We can also Delete a record of an ID.

protected void btnDelete_Click(object sender, EventArgs e)
        {
            int Id = Convert.ToInt32(txtDeleteId.Text);

            ImportantDBEntities dbEntities = new ImportantDBEntities();
            EF_Employee employee = dbEntities.EF_Employee.SingleOrDefault(i => i.Id == Id);
            dbEntities.EF_Employee.DeleteObject(employee);
            dbEntities.SaveChanges();

            FillEmployeeGrid();
        }

Update is also not a big deal .

protected void btnUpdate_Click(object sender, EventArgs e)
        {
            int id = Convert.ToInt32(TxtUpdateId.Text);

            ImportantDBEntities dbEntities = new ImportantDBEntities();
            EF_Employee employee = dbEntities.EF_Employee.SingleOrDefault(i => i.Id == id);
            employee.Address = txtUpdateAddress.Text;
            dbEntities.SaveChanges();

            FillEmployeeGrid();
        }

Hope , it helps them who are new to EF .
I will write more deeper things related to EF in Part 2 .So keep an eye on my Site.

Till Then , Cheers …

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2 thoughts on “EntityFramework in C# – Part1 : Welcome To EF

  1. Pingback: EntityFramework in C# – Part2 : Calling MS SQL StoredProcedure | Shahjada Talukdar MasooM

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