CODEWITHSUNDEEP
c#sql-server
bobby
bobby

Reputation: 11

C# showing only the values from sql table with null value

I am connecting to an SQL server. I have a column which has date and time and another which has the user name. Once i connect to the database it shows everything except the null values in the column of date and time. I need to show only the column of data and time which holds null values and the user with the null value. How do i Display the null values but only the null values?

Below is my code:

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace sql_connection
{
class Program
{
    static void Main(string[]args)
{

        string conn=null;
        SqlConnection connection;
        conn=("Data Source=Database\\SQL2012;Initial Catalog=Table;User ID=user;Password=example");

         connection=new SqlConnection(conn);
         try{

             connection.Open();
             Console.Writeline("Connection Open!");
             SqlCommand cmd= new SqlCommand("SELECT tabledateandtime,tableuser FROM [dbo].[tb_Showingnull]");
             cmd.Connection = connection;
             SqlDataReader reader = cmd.ExecuteReader();
             while(reader.Read())
              {

                   Console.WriteLine("{1} , {0}", reader["tabledateandtime"].ToString(),  reader["tableuser"].ToString()));

               }

               connection.Close();
                }

                catch(Exception ex)
               {
                   Console.WriteLine(ex.Message);
                }

                }
            }
      }

Upvotes: 0

Views: 963

Answers (2)

Donal
Donal

Reputation: 32713

Based on OP's last comment, I have updated the code below to display NULL if the date is NULL otherwise show the date.

while(reader.Read())
{
    Console.WriteLine("{1}, {0}", 
       reader["tableuser"].ToString(),  
       reader["tabledateandtime"] == DBNull.Value ? "NULL" : reader["tabledateandtime"].ToString());
}

If you just want to return only records that have a null date, then just update your SQL to this:

SqlCommand cmd = new SqlCommand("SELECT tabledateandtime, tableuser" +
    " FROM [dbo].[tb_Showingnull] WHERE tabledateandtime IS NULL OR tableuser IS NULL");

Upvotes: 1

Jurgen Camilleri
Jurgen Camilleri

Reputation: 3589

I think I finally understood what you want - check this out: 

while(reader.Read())
{
    Console.WriteLine("{1} , {0}", reader["tabledateandtime"] == DBNull.Value ? "NULL" : reader["tabledateandtime"].ToString(),  reader["tableuser"].ToString()));
}

Upvotes: 0

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