Find data by primary key, if not found add to database : DataColumn « ADO.Net « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. ADO.Net
3. DataColumn

using System;
using System.Data;            
using System.Data.SqlClient;  
using System.Collections.Generic;
using System.Text;


  class Program
  {
    static void Main(string[] args)
    {
      SqlConnection thisConnection = new SqlConnection(
                @"Data Source=.\SQLEXPRESS;" +
                @"AttachDbFilename='NORTHWND.MDF';" +
                @"Integrated Security=True;Connect Timeout=30;User Instance=true");
      SqlDataAdapter thisAdapter = new SqlDataAdapter("SELECT CustomerID, CompanyName FROM Customers", thisConnection);

      SqlCommandBuilder thisBuilder = new SqlCommandBuilder(thisAdapter);

      DataSet thisDataSet = new DataSet();

      thisAdapter.Fill(thisDataSet, "Customers");

      Console.WriteLine("# rows before change: {0}",thisDataSet.Tables["Customers"].Rows.Count);

      DataColumn[] keys = new DataColumn[1];
      keys[0] = thisDataSet.Tables["Customers"].Columns["CustomerID"];
      thisDataSet.Tables["Customers"].PrimaryKey = keys;

      DataRow findRow = thisDataSet.Tables["Customers"].Rows.Find("1");
      if (findRow == null)
      {
        DataRow thisRow = thisDataSet.Tables["Customers"].NewRow();
        thisRow["CustomerID"] = "1";
        thisRow["CompanyName"] = "Abc Ltd.";
        thisDataSet.Tables["Customers"].Rows.Add(thisRow);
        if ((findRow = thisDataSet.Tables["Customers"].Rows.Find("1")) != null)
        {
          Console.WriteLine("success");
        }
      }
      thisAdapter.Update(thisDataSet, "Customers");
      Console.WriteLine(thisDataSet.Tables["Customers"].Rows.Count);
      thisConnection.Close();
    }
  }