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DataSet 

private void button9_Click(object sender, EventArgs e)

{

            string sSQL = "SELECT * FROM [dbo].[UserTable]";

            string cn_txt = Properties.Settings.Default.Database1ConnectionString;

            SqlConnection cn_connection = new SqlConnection(cn_txt);

            if (cn_connection.State != ConnectionState.Open)

            {

                cn_connection.Open();

            }

            DataSet tables = new DataSet();

            SqlDataAdapter adapter = new SqlDataAdapter(sSQL, cn_connection);

            adapter.Fill(tables);

            dataGridView1.DataSource = tables.Tables[0];

}

Якщо перший запит пакету не проходить, то другий не виконується

 private void button8_Click(object sender, EventArgs e)

        {

            string cn_txt = Properties.Settings.Default.Database1ConnectionString;

            SqlConnection cn_connection = new SqlConnection(cn_txt);

            if (cn_connection.State != ConnectionState.Open)

            {

                cn_connection.Open();

            }

            string sSQL = "INSERT INTO [dbo].[UserTable](Name, Level, Team) VALUES('" + 

                                                                                            textBox1.Text + "','" +

                                                                                            textBox2.Text + "','" +

                                                                                            textBox3.Text + "') ";

            SqlTransaction transaction = cn_connection.BeginTransaction();

            SqlCommand command = cn_connection.CreateCommand(); 

            command.Transaction = transaction;

            command.CommandText = sSQL;

            command.ExecuteNonQuery();

            command.CommandText = sSQL;

            command.ExecuteNonQuery();

            transaction.Commit();

            command.Dispose();

            cn_connection.Close();

        }

COUNT

async private void button7_Click(object sender, EventArgs e)

{

            string cn_txt = Properties.Settings.Default.Database1ConnectionString;

            SqlConnection cn_connection = new SqlConnection(cn_txt);

            cn_connection.Close();

            if (cn_connection.State != ConnectionState.Open)

            {

                await cn_connection.OpenAsync();

            }

            string sSQL = "SELECT COUNT (Id) FROM [dbo].[UserTable];";

            SqlCommand command = new SqlCommand(sSQL, cn_connection);

            object count = await command.ExecuteScalarAsync();

            MessageBox.Show("count = " + count.ToString());

            command.Dispose();

            cn_connection.Close();

}