c# - How to handle multiple ResultSets, each with multiple Rows? IDataReader.NextResult() ending Read()

Question

How to handle multiple ResultSets, each with multiple Rows? The call to NextResult() breaks the while loop.

Some of my SPs return multiple ResultSets. I'm handling these with NextResult() but when I do and my SP only has a single ResultSet, I see the while loop with Read() finishes leaving me with only the first Row.

Without the call to NextResult() I get all the rows for the first ResultSet but of course the second and subsequent ResultSets don't get processed?

using (IDataReader reader = storedProcedure.ExecuteReader(
    CommandBehavior.CloseConnection, parameterNames as string[], arguments))
{
    while (reader.Read())
    {
        ArrayList row = new ArrayList();
        for (int j = 0; j < reader.FieldCount; ++j)
        {
            object rowValue = reader.GetValue(j);

            row.Add(rowValue);
        }

        reader.NextResult();//next resultset, breaks out of the  while
    }
}

Answer 1

You need to create two nested loops.

• The outer loop should iterate over result sets and should have NextResult at the end
• The inner loop should iterate over rows in a result set and should have Read at the beginning.

Something like:

using (IDataReader reader = ...) { 
  // Process all result sets
  do {
    // Process all elements in the current result set
    while (reader.Read()) { 
      ArrayList row = new ArrayList(); 
      for (int j = 0; j < reader.FieldCount; ++j) { 
        object rowValue = reader.GetValue(j); 
        row.Add(rowValue); 
      } 
      // TODO: Do something with 'row'
    }
  } while (reader.NextResult())
}