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Offline or Disconnected Database Access

The following code shows how to use insert, delete and update in the Offline method of ADO.NET. With the help of ADO.NET we use the techniqueS of DataSet, DataAdapter, DataRowCollection, DataRow, DataColumn etc. for working with the database.


//FOR INSERTION IN DATABASE

SqlConnection conn = new SqlConnection("Server=(local);DataBase=Rohit;Integrated Security=SSPI");
            conn.Open();

            SqlDataAdapter vAdap = new SqlDataAdapter("Select * from empNew", conn);
            DataSet vDs = new DataSet();
            vAdap.Fill(vDs, "EmpNew");

            DataTable vDt = vDs.Tables["EmpNew"];

            DataRow vDr = vDt.NewRow();
            vDr["Empno"] = Convert.ToInt32(textBox1.Text);
            vDr["Ename"] = textBox2.Text;
            vDr["Salary"] = Convert.ToInt32(textBox3.Text);

            vDt.Rows.Add(vDr);
            //Now we need to sync the data back to the database
            if (vDs.HasChanges())
            {
                if (conn.State == ConnectionState.Closed)
                {
                    conn.Open();
                }
                SqlCommandBuilder vCmdBuilder = new SqlCommandBuilder(vAdap);
                vAdap.Update(vDs, "EmpNew");
                MessageBox.Show("Record successfully saved");
               
            }
            conn.Close();

//FOR UPDATION

SqlConnection conn = new SqlConnection("Server=(local);DataBase=Rohit;Integrated Security=SSPI");
            conn.Open();
            SqlDataAdapter vAdap = new SqlDataAdapter("Select * from empNew", conn);
            DataSet vDs = new DataSet();
            vAdap.FillSchema(vDs, SchemaType.Source);
            vAdap.MissingSchemaAction = MissingSchemaAction.AddWithKey;

            vAdap.Fill(vDs, "EmpNew");
            DataTable vDt = vDs.Tables["EmpNew"];
           
            DataRowCollection vDrc = vDt.Rows;
            DataRow vDr=vDrc.Find("101");
            if (vDr == null)
            {
                MessageBox.Show("Sorry no record found");
            }
            else
            {
                vDr.BeginEdit();
                //New values for updation
                vDr["Ename"] = "Microsoft";
                vDr["Salary"] = 120000;
                vDr.EndEdit();

                //Now we need to sync the data back to the database
                if (vDs.HasChanges())
                {
                    if (conn.State == ConnectionState.Closed)
                    {
                        conn.Open();
                    }
                    SqlCommandBuilder vCmdBuilder = new SqlCommandBuilder(vAdap);
                    vAdap.Update(vDs, "EmpNew");
                    MessageBox.Show("Record successfully updated");

                }
                conn.Close();
            }
        }

FOR DELETION

SqlConnection conn = new SqlConnection("Server=(local);DataBase=Rohit;Integrated Security=SSPI");
            conn.Open();
            SqlDataAdapter vAdap = new SqlDataAdapter("Select * from empNew", conn);
            DataSet vDs = new DataSet();
            vAdap.FillSchema(vDs, SchemaType.Source);
            vAdap.MissingSchemaAction = MissingSchemaAction.AddWithKey;

            vAdap.Fill(vDs, "EmpNew");
            DataTable vDt = vDs.Tables["EmpNew"];


            DataRowCollection vDrc = vDt.Rows;
            DataRow vDr = vDrc.Find("101");
            if (vDr == null)
            {
                MessageBox.Show("Sorry no record found");
            }
            else
            {
                //New values for updation
                vDr.Delete();
                //Now we need to sync the data back to the database
                if (vDs.HasChanges())
                {
                    if (conn.State == ConnectionState.Closed)
                    {
                        conn.Open();
                    }
                    SqlCommandBuilder vCmdBuilder = new SqlCommandBuilder(vAdap);
                    vAdap.Update(vDs, "EmpNew");
                    MessageBox.Show("Record successfully updated");

                }
                conn.Close();

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