public static void Main(string[] args)
{
Npgsql.NpgsqlConnection v_con = null;
Npgsql.NpgsqlCommand v_cmd = null;
Npgsql.NpgsqlDataReader v_reader = null;
System.Data.DataTable v_table;
System.Data.DataRow v_row;
Console.WriteLine("Exemplo PostgreSQL usando DataReader");
Console.WriteLine();
try
{
// 1) instanciando Connection
v_con = new Npgsql.NpgsqlConnection(
"Server=127.0.0.1;Port=5432;Database=lugares;User ID=postgres;Password=knightnote"
);
// 2) abrindo Connection
v_con.Open();
// 3) instanciando Command
v_cmd = new Npgsql.NpgsqlCommand("select * from estados", v_con);
// 4) executando DataReader
v_reader = v_cmd.ExecuteReader();
// 5) criando DataTable
v_table = new System.Data.DataTable("RESULTADO");
for (int i = 0; i < v_reader.FieldCount; i++)
v_table.Columns.Add(v_reader.GetName(i), typeof(string));
// 6) alimentando DataTable
while (v_reader.Read())
{
v_row = v_table.NewRow();
for (int i = 0; i < v_reader.FieldCount; i++)
v_row[i] = v_reader[i].ToString();
v_table.Rows.Add(v_row);
}
// 7) usando DataTable (imprimindo na tela)
foreach (System.Data.DataColumn c in v_table.Columns)
Console.Write("{0} ", c.ColumnName);
Console.WriteLine();
foreach (System.Data.DataRow r in v_table.Rows)
{
foreach (System.Data.DataColumn c in v_table.Columns)
Console.Write("{0} ", r[c].ToString());
Console.WriteLine();
}
}
catch (Npgsql.NpgsqlException ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
// 8) liberando Command
if (v_cmd != null)
{
v_cmd.Cancel();
v_cmd.Dispose();
v_cmd = null;
}
// 9) liberando DataReader
if (v_reader != null)
{
v_reader.Close();
v_reader = null;
}
// 10) fechando e liberando Connection
if (v_con != null)
{
v_con.Close();
v_con = null;
}
}
Console.ReadKey();
}
public override void Cancel()
{
cmd.Cancel();
}
