System.InvalidOperationException : Please help

[AprNgp]

I am reading some data from the database, but its giving System.InvalidOperationException: my code is as follows :

LoadInfo l = new LoadInfo();
l.LoadFromSQL(Session["username"].ToString());

the class LoadInfo has the member function LoadFromSQL as follows,

public void LoadFromSQL(string username)
{
SqlDataReader reader = null;
reader = SqlMember.ExecuteReader("SELECT UserId FROM Members WHERE UserName=@username", username);
m.LoadFromReader(reader);
}

the SqlMember class has the static member function ExecuteReader as following:

static public SqlDataReader ExecuteReader(string qs,string username)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
SqlCommand cmd = new SqlCommand(qs, conn);
cmd.Parameters.Add(new SqlParameter ("@username","a"));
conn.Open();
if (cmd.ExecuteScalar() == null)
{
int i;
i = 0;
}
return cmd.ExecuteReader();
}

the LoadFromReader member function of SqlMember class is as follows:

public void LoadFromReader(SqlDataReader reader)
{
this.UserId = (int)reader["UserId"];
this.FirstName = (string)reader["FirstName"];
this.LastName = (string)reader["LastName"];
this.CityId = (int)reader["CityId"];
this.CountryId = (int)reader["CountryId"];
this.Mood = (byte)reader["Mood"];
}

The exception is occurring in the above function, while reading the data from the reader this.UserId = (int)reader["UserId"]; if this line is commented (//) the exception occurs in the next line. Error:

Invalid attempt to read when no data is present.

:confused: The username provided by the session object is available in the database. Please help me to solve this problem. :( Is there any way to know, if the ExecuteReader returned any values ?

Apurv

[Rutvik Dave]

I think it is showing you the error because you forgot to call Read() also your query returns only UserID and you are reading whole row. so change the

Select UserID FROM Members WHERE UserName=@username

to

Select UserID,FirstName,LastName,CityId,CountryId,Mood FROM Members WHERE UserName=@username

in the LoadFromReader()

public void LoadFromReader(SqlDataReader reader)
{
if(reader.Read())
{
this.UserId = (int)reader["UserId"];
this.FirstName = (string)reader["FirstName"];
this.LastName = (string)reader["LastName"];
this.CityId = (int)reader["CityId"];
this.CountryId = (int)reader["CountryId"];
this.Mood = (byte)reader["Mood"];
}
else
// code for no row found for the specific user...
}

also change the ExecuteScalar() to ExecuteReader() because now you are getting more than one values.

[AprNgp]

thanx .... will try with the changes ...

Apurv

[AprNgp]

Its working thanks .....

Apurv