DbProviderFactory(その2)

前回の続き(?)。
Providerに依存しないコードを書いてみた。

ConnectionStringSettings css = ConfigurationManager.ConnectionStrings["MyConnection"];
DbProviderFactory factory = DbProviderFactories.GetFactory(css.ProviderName);

DbConnectionStringBuilder sb = factory.CreateConnectionStringBuilder();
sb.ConnectionString = css.ConnectionString;
//この辺はProviderに依存するよなぁ
sb.Add("Password", "xxxx");

using (DbConnection connection = factory.CreateConnection())
{
    connection.ConnectionString = sb.ConnectionString;
    connection.Open();
    //factory.CreateCommand()でもいいけど、こっちの方が素直な気がする。
    DbCommand command = connection.CreateCommand();

    //ここも依存することが多いよね。
    command.CommandText = "SELECT * FROM TABLE1 WHERE ID = ?";
    DbParameter p = factory.CreateParameter();
    p.DbType = DbType.Int32;
    p.Value = 1;
    command.Parameters.Add(p);

    using (DbDataReader reader = command.ExecuteReader())
    {
        while (reader.Read())
        {
            reader.GetInt32(0);
        }
    }
}