0

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

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  • 1
    __avd 1,826   7 Years Ago

    You missed Read() method. [code=c#] if (dataReader4.Read()) var=dataReader4.IsDBNull(0); } [/code] Read More

  • Hi, Read example [URL="http://msdn.microsoft.com/en-us/library/system.data.oledb.oledbdatareader(VS.71).aspx"]here[/URL]. 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. Read More

1

You missed Read() method.

if (dataReader4.Read())
   var=dataReader4.IsDBNull(0);
}
1

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.

0

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!!!

0

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

0

Hi

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

:)
Tank50

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