SqlDataAdapter with using keyword

问题

Is this the following code healthy? Or I don't need to use the using keyword as the SqlDataAdapter will handle closing the connection?

public static DataSet Fetch(string sp, SqlParameter [] prm)
{
    using (SqlConnection con = new SqlConnection(ConStr))
    {
        using (SqlCommand cmd = con.CreateCommand())
        {
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = sp;
            cmd.Parameters.AddRange(prm);

            using (SqlDataAdapter dta = new SqlDataAdapter(cmd))
            {
                DataSet dst = new DataSet();
                dta.Fill(dst);

                return dst;
            }
        }
    }
}

@MarkGravell I need a suggestions here, I am really looking to use DataReader, but I was looking all the time to use the using keyword to ensure closing the connections. Where with DataReader we can not use it because it will close the connection if we want to return the DataReader back to some method. So do you think the following technique is fine with DataReader and the using keyword:

public static SqlDataReader Fetch(string sp, SqlParameter [] prm)
{
    SqlCommand cmd = new SqlConnection(ConStr).CreateCommand();
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.CommandText = sp;
    cmd.Parameters.AddRange(prm);
    cmd.Connection.Open();

    return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}

using (SqlDataReader dtrPrize = Sql.Fetch("SelectPrize", new SqlParameter[] { new SqlParameter("id", id) }))
{
    dtrPrize.Read();

    Prize prize = new Prize();
    prize.id = (int)dtrPrize[dtrPrize.GetOrdinal("id")];
    prize.artitle = (string)dtrPrize[dtrPrize.GetOrdinal("artitle")];
    prize.entitle = (string)dtrPrize[dtrPrize.GetOrdinal("entitle")];
    prize.ardetail = (string)dtrPrize[dtrPrize.GetOrdinal("ardetail")];
    prize.endetail = (string)dtrPrize[dtrPrize.GetOrdinal("endetail")];
    prize.image = (string)dtrPrize[dtrPrize.GetOrdinal("image")];
    prize.theme = (string)dtrPrize[dtrPrize.GetOrdinal("theme")];
    prize.price = (int)dtrPrize[dtrPrize.GetOrdinal("price")];
    prize.audience = (int)dtrPrize[dtrPrize.GetOrdinal("audience")];
    prize.type = (byte)dtrPrize[dtrPrize.GetOrdinal("type")];
    prize.status = (byte)dtrPrize[dtrPrize.GetOrdinal("status")];
    prize.voucher = (string)dtrPrize[dtrPrize.GetOrdinal("voucher")];
    prize.supplierid = (int)dtrPrize[dtrPrize.GetOrdinal("supplierid")];
    prize.created = (DateTime)dtrPrize[dtrPrize.GetOrdinal("created")];
    prize.updated = (DateTime)dtrPrize[dtrPrize.GetOrdinal("updated")];

    return prize;
}

回答1:

Healthy-ish; personally I'd say the unhealthy bit is the bit where it makes use of DataSet and DataAdapter, but that is perhaps just my personal bias.

Yes, you should dispose the adapter etc here (which is what the using does for you, obviously).

As a trivial pointless tidy, you can stack the usings - just makes it a little less verbose:

using (SqlConnection con = new SqlConnection(ConStr))
using (SqlCommand cmd = con.CreateCommand())
{

回答2:

It will be enough to leave just the first using (the one on the Connection) because disposing the connection will dispose everything you need disposed.

However, there is no harm disposing everything, just a bit more code.

来源：https://stackoverflow.com/questions/15333522/sqldataadapter-with-using-keyword

标签

ado.net

dispose

using

sqldataadapter