Insert,delete and update using LinQ in Asp.net

Step 1:

Create a new Web application project:

(or)

File --> New Website

Step 2:

Create a Web Form:

<asp:Button ID="btnView" runat="server" Text="View" OnClick="btnView_Click" />
    <asp:Button ID="btnAddNew" runat="server" Text="Add New" OnClick="btnAddNew_Click" />
    <table id="tblForm" runat="server">
        <tr>
            <td>Country Name:</td>
            <td><asp:TextBox ID="txtCountryName" runat="server"></asp:TextBox></td>
        </tr>
        <tr>
            <td>Country Code:</td>
            <td><asp:TextBox ID="txtCountryCode" runat="server"></asp:TextBox></td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:Button ID="btnSave" runat="server" Text="Add" 
  OnClick="btnSave_Click" />
                <asp:Button ID="btnUpdate" runat="server" Text="Update" 
  OnClick="btnUpdate_Click" />
                <asp:Button ID="btnCancel" runat="server" Text="Cancel" 
  OnClick="btnCancel_Click" />
            </td>
        </tr>
    </table>
    <table id="tblGrid" runat="server">
        <tr>
            <td><asp:Label ID="lblID" runat="server" Visible="false"></asp:Label>
                <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" 
  OnRowCommand="GridView1_RowCommand">
                    <Columns>
                        <asp:BoundField DataField="Countryid" HeaderText="ID" />
                        <asp:BoundField DataField="CountryName" 
   HeaderText="Country Name" />
                        <asp:TemplateField>
                            <ItemTemplate>
                                <asp:LinkButton ID="lnkEdit" runat="server" 
    CommandArgument='<%# Eval("Countryid")%>'
                                    CommandName="cmdEdit" Text="Edit"></asp:LinkButton>
                                  ---  
                                <asp:LinkButton ID="lnkDelete" runat="server" 
    CommandArgument='<%# Eval("Countryid")%>'
                                    CommandName="cmdDelete" Text="Delete">
        </asp:LinkButton>
                            </ItemTemplate>
                        </asp:TemplateField>
                    </Columns>
                </asp:GridView>
            </td>
        </tr>
    </table>

Step 3:

Add a new item – Linq to SQL classes:

Step 4:

Create a database table -- tblCountry:

CREATE TABLE [dbo].[tblCountry](
 [Countryid] [int] IDENTITY(1,1) NOT NULL,
 [CountryName] [nvarchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 [CountryCode] [nvarchar](10) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 [Status] [nvarchar](10) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
 
 CONSTRAINT [PK_tblCountry] PRIMARY KEY CLUSTERED 
(
 [Countryid] ASC
)WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

Step 5:

Connect the database to the project:

Step 6:

Select the table for Linq table integration:
To change a .dbml Name

Step 7:

Set database connection string in web.config file:

<appSettings>
  <add key="constr" value="Data Source = machinename\SQLEXPRESS;
 Initial Catalog=test;User ID=tuser; password=tpass"/>
</appSettings>

Step 8:

Write Insert record method:

protected void btnSave_Click(object sender, EventArgs e)
        {
            using(DLCountryiesDataContext countries = new DLCountryiesDataContext())
            {
                tblCountry country = new tblCountry
                 {
                     CountryName = txtCountryName.Text.Trim(),
                     CountryCode = txtCountryCode.Text.Trim(),
                     Status = "Active"
                 };
                countries.Connection.ConnectionString = 
  System.Configuration.ConfigurationManager.AppSettings["constr"];
                countries.tblCountries.InsertOnSubmit(country);
                countries.SubmitChanges();
                ViewData();
            }
        }

Step 9:

Write method View Records in Gridview:

private void ViewData()
        {
            ClearForm();
            DLCountryiesDataContext db = new DLCountryiesDataContext();
            db.Connection.ConnectionString = 
  System.Configuration.ConfigurationManager.AppSettings["constr"];
            var country =
                from c in db.tblCountries
                select c;

            GridView1.DataSource = country;
            GridView1.DataBind();
        }

Step 10:

Write methods for edit and delete records:

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            if (e.CommandName == "cmdEdit")
            {
                ClearForm();
                DLCountryiesDataContext db = new DLCountryiesDataContext();
                db.Connection.ConnectionString = 
  System.Configuration.ConfigurationManager.AppSettings["constr"];
                var country =
                    from c in db.tblCountries
                    where (c.Countryid == Convert.ToInt32(e.CommandArgument.ToString()))
                    select c;
                lblID.Text = e.CommandArgument.ToString();
                foreach (tblCountry cntry in country)
                {
                    txtCountryName.Text = cntry.CountryName;
                    txtCountryCode.Text = cntry.CountryCode;
                }
                btnSave.Visible = false;
                btnUpdate.Visible = true;

                ShowForm();
}
            if (e.CommandName == "cmdDelete")
            {
                DLCountryiesDataContext db = new DLCountryiesDataContext();
                db.Connection.ConnectionString = 
  System.Configuration.ConfigurationManager.AppSettings["constr"];
                var country =
                    from c in db.tblCountries
                    where (c.Countryid == Convert.ToInt32(e.CommandArgument.ToString()))
                    select c;

                db.tblCountries.DeleteAllOnSubmit(country);
                db.SubmitChanges();
                ViewData();
            }
        }

Step 11:

Write method for update record:

protected void btnUpdate_Click(object sender, EventArgs e)
        {
            DLCountryiesDataContext db = new DLCountryiesDataContext();
            db.Connection.ConnectionString = 
  System.Configuration.ConfigurationManager.AppSettings["constr"];

            var country = db.tblCountries.Single
  (p => p.Countryid == Convert.ToInt32(lblID.Text));
            country.CountryName = txtCountryName.Text.Trim();
            country.CountryCode = txtCountryCode.Text.Trim();
            db.SubmitChanges();
            ViewData();
        }

Step 12:

Common methods for page (it's not mandatory to use in page):

protected void btnView_Click(object sender, EventArgs e)
        {         
            ViewData();
            HideForm();
        }

        protected void btnAddNew_Click(object sender, EventArgs e)
        {
            ShowForm();
            btnSave.Visible = true;
            btnUpdate.Visible = false;            
        }

        protected void btnCancel_Click(object sender, EventArgs e)
        {   
            ViewData();
            HideForm();
        }
        
        private void HideForm()
        {
            tblForm.Visible = false;
            tblGrid.Visible = true;
            btnView.Visible = false;
            btnAddNew.Visible = true;            
        }
        
        private void ShowForm()
        {
            tblForm.Visible = true;
            tblGrid.Visible = false;
            btnView.Visible = true;
            btnAddNew.Visible = false;
        }
        
        private void ClearForm()
        {
            txtCountryCode.Text = "";
            txtCountryName.Text = "";
        }

Step 13:

Run the project.

End.