Bind ASP.Net DropDownList and Insert Data to Different Table using C# and VB.Net

Hey Shifa,

Please refer below sample.

HTML

<table>
    <tr>
        <td>
            Name
        </td>
        <td>
            <asp:TextBox runat="server" ID="txtName" />
        </td>
    </tr>
    <tr>
        <td>
            Department
        </td>
        <td>
            <asp:DropDownList runat="server" ID="ddlDepartMent">
            </asp:DropDownList>
        </td>
    </tr>
    <tr>
        <td>
            <asp:Button Text="Save" runat="server" OnClick="Save" />
        </td>
    </tr>
</table>
<br />
<asp:GridView runat="server" ID="gvTeachers" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="TeacherId" HeaderText="TeacherId" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="DepartmentId" HeaderText="DepartmentId" />
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Data;
using System.Data.SqlClient;
using System.Configuration;

VB.Net

Imports System.Data.SqlClient
Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        string query = "SELECT CustomerId, Country FROM Customers";
        DataTable dt = GetData(query);
        ddlDepartMent.DataSource = dt;
        ddlDepartMent.DataValueField = "CustomerId";
        ddlDepartMent.DataTextField = "Country";
        ddlDepartMent.DataBind();
    }
}

private DataTable GetData(string query)
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand(query, con))
        {
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                using (DataTable dt = new DataTable())
                {
                    da.Fill(dt);
                    return dt;
                }
            }
        }
    }
}
protected void Save(object sender, EventArgs e)
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("INSERT INTO TeacherName(Name, DepartmentId) VALUES(@Name,@DepartmentId)", con))
        {
            cmd.Parameters.AddWithValue("@Name", txtName.Text);
            cmd.Parameters.AddWithValue("@DepartmentId", ddlDepartMent.SelectedValue);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
    string query = "SELECT TeacherId, Name, DepartmentId FROM TeacherName";
    DataTable dt = GetData(query);
    this.gvTeachers.DataSource = dt;
    this.gvTeachers.DataBind();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim query As String = "SELECT CustomerId, Country FROM Customers"
        Dim dt As DataTable = GetData(query)
        ddlDepartMent.DataSource = dt
        ddlDepartMent.DataValueField = "CustomerId"
        ddlDepartMent.DataTextField = "Country"
        ddlDepartMent.DataBind()
    End If
End Sub

Private Function GetData(ByVal query As String) As DataTable
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using cmd As SqlCommand = New SqlCommand(query, con)
            Using da As SqlDataAdapter = New SqlDataAdapter(cmd)
                Using dt As DataTable = New DataTable()
                    da.Fill(dt)
                    Return dt
                End Using
            End Using
        End Using
    End Using
End Function

Protected Sub Save(ByVal sender As Object, ByVal e As EventArgs)
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using cmd As SqlCommand = New SqlCommand("INSERT INTO TeacherName(Name, DepartmentId) VALUES(@Name,@DepartmentId)", con)
            cmd.Parameters.AddWithValue("@Name", txtName.Text)
            cmd.Parameters.AddWithValue("@DepartmentId", ddlDepartMent.SelectedValue)
            con.Open()
            cmd.ExecuteNonQuery()
            con.Close()
        End Using
    End Using

    Dim query As String = "SELECT TeacherId, Name, DepartmentId FROM TeacherName"
    Dim dt As DataTable = GetData(query)
    Me.gvTeachers.DataSource = dt
    Me.gvTeachers.DataBind()
End Sub

Screenshot