I have tried to write a program use ado.net provide by firebird,
I have create a connection and use the connection execute a command
return a DataReader, I proceed the DataReader in a loop, I create
another command use the same connection and I want to get the data
according the first datareader's value, but when I call
cmd.ExecuteScalar(), exception occurs, the exception's message is

"There is already an open DataReader associated with this Connection
which must be closed first"

I wonder to know, can a connection object has some DataReader objects
same time?

Or how can I solve the problem?

any help are appreciate