DbDataReader.GetFieldValue(Of T) Method
Synchronously gets the value of the specified column as a type.
Assembly: System.Data (in System.Data.dll)
The connection drops or is closed during the data retrieval.
The SqlDataReader is closed during the data retrieval.
There is no data ready to be read (for example, the first Read hasn't been called, or returned false).
Tried to read a previously-read column in sequential mode.
There was an asynchronous operation in progress. This applies to all Get* methods when running in sequential mode, as they could be called while reading a stream.
Trying to read a column that does not exist.
T doesn’t match the type returned by SQL Server or cannot be cast.