dataReader doesn't read

Violeta Popa

Hi :) I am trying to read some information from the database, but i don't know why this reader doesn't work. I've checked in the database and i have the client with that id.

int nr_dauna = 0;

string selectDauna = "SELECT * FROM dauna WHERE id_client='" + 16 + "'";

SqlCommand executaSelectDauna = new SqlCommand(selectDauna, conn);

SqlDataReader rdr_dauna = executaSelectDauna.ExecuteReader();

rdr_dauna.Read();

nr_dauna = Convert.ToInt32(rdr_dauna["nr_dauna"]);

rdr_dauna.Close();

MessageBox.Show(nr_dauna.ToString());

It's sth wrong? Or maybe there is another way of reading database info?Thanks!

5 Replies

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Shankar M13y ago
Hi Violeta,

You can use the HasRows property of the reader object to check that rows are returns by the ExecuteReader() Method and

while(reader.Reader())
{
MessageBox.Show (reader["ENAME"].ToString());
}

To Loop through the data.
Jignesh Trivedi13y ago
hi,

try

string selectDauna = "SELECT nr_dauna FROM dauna WHERE id_client='" + 16 + "'";
SqlCommand executaSelectDauna = new SqlCommand(selectDauna, conn);
conn.Open();
SqlDataReader rdr_dauna = executaSelectDauna.ExecuteReader();
if (rdr_dauna.HasRows == true)
{
    while (rdr_dauna.Read())
    {
nr_dauna = Convert.ToInt32(rdr_dauna.GetInt32(0));
    }
}
rdr_dauna.Close();

it might work for you.
Javeed M Shaikh13y ago
can do a quick watch on the line rdr_dauna.HasRows and see the value there?
Violeta Popa13y ago
I've tried this, but it doesn't show neither true nor false :|

int nr_dauna = 0;
string selectDauna = "SELECT * FROM dauna WHERE id_client='" + 16 + "'";
SqlCommand executaSelectDauna = new SqlCommand(selectDauna, conn);
SqlDataReader rdr_dauna = executaSelectDauna.ExecuteReader();
if (rdr_dauna.HasRows == true)
MessageBox.Show("true");
else
MessageBox.Show("false");
rdr_dauna.Read();
nr_dauna = Convert.ToInt32(rdr_dauna["nr_dauna"]);
rdr_dauna.Close();
Javeed M Shaikh13y ago
are you getting any errors?

try the following command before you give rdr_dauna.Read(); and see if this is true
rdr_dauna.HasRows