Check if DataTable Column value is null or not in ASP.Net using C# and VB.Net

Hi Jonsey ,

Refer below code.

Database

I have made use of the following table Customers with the schema as follows.

I have already inserted few records in the table.

You can download the database table SQL by clicking the download link below.

Download SQL file

Namespaces

C#

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

VB.Net

Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

private void BindGrid()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    string query = "SELECT CustomerId,Name,Country FROM Customers";
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter(query, con))
        {
            using (DataTable dt = new DataTable())
            {
                sda.Fill(dt);
                foreach (DataRow rs in dt.Rows)
                {
                    if (rs["Name"] == DBNull.Value)
                    {
                        Response.Write("Value is Null" + "<br/>");
                    }
                    else if (string.IsNullOrEmpty(rs["Name"].ToString()))
                    {
                        Response.Write("Value is Empty" + "<br/>");
                    }
                    else
                    {
                        Response.Write("Value is not Null" + "<br/>");
                    }
                }
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
    Me.BindGrid()
End If
End Sub

Private Sub BindGrid()
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Dim query As String = "SELECT CustomerId,Name,Country FROM Customers"
Using con As SqlConnection = New SqlConnection(constr)
    Using sda As SqlDataAdapter = New SqlDataAdapter(query, con)
        Using dt As DataTable = New DataTable()
            sda.Fill(dt)
            For Each rs As DataRow In dt.Rows
                If IsDBNull(rs("Name")) Then ' Null check
                    Response.Write("Value is Null" & "<br/>")
                ElseIf String.IsNullOrEmpty(rs("Name").ToString()) Then ' Empty check
                    Response.Write("Value is Empty" & "<br/>")
                Else
                    Response.Write("Value is not Null" & "<br/>")
                End If
            Next
        End Using
    End Using
End Using
End Sub