Error in reading DataReader

[Tank50]

Hi

I want to read the content in datareader.So I use below coding to do that
if (dataReader4.IsDBNull(0)){

}
but I run above coding it gave me an error meassage.The error Meassage is
"Invalid attempt to read when no data is present".

then I use below coding
dataReader4["Email"]==null
but It also gave me above error meassage.There is no record for that field,that only for one record,for othere records there are email address.

Thanks
Tank50

[__avd]

You missed Read() method.

if (dataReader4.Read())
   var=dataReader4.IsDBNull(0);
}

[DangerDev]

Hi,
Read example here . It will help you. You have to call dataReader4.Read() before reading it. If still problem persist please post code what you have done so far.

[maestridaniele]

Hi

I want to read the content in datareader.So I use below coding to do that if (dataReader4.IsDBNull(0)){

} but I run above coding it gave me an error meassage.The error Meassage is "Invalid attempt to read when no data is present".

then I use below coding dataReader4["Email"]==null but It also gave me above error meassage.There is no record for that field,that only for one record,for othere records there are email address.

Thanks Tank50

//****************************************************
Hi,
try this code to read datareader...// Instance a new object
Object a = new Object();

// Check if datareader is null
if (datareader == null)
return;

// Get data from datareader
while (datareader.Read())
{
// Code example...
a = datareader.GetValue(0);
}

Hope it works for you...
:idea: See ya!!!

[djjaries]

It looks like you start using the reader without reading some data first.

void ReadData(SqlConnection conn, string sql)
SqlDataReader datareader;
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandText = sql;
datareader = cmd.ExecuteReader();
while (datareader.Read()) {
 // perform your code here
}
}

Cheers,
Dennis

[Tank50]

Hi

Thanks guys.I was in greate trouble coz of this error meassage.Now it ok ,I miss datareader.Read() part.

:)
Tank50