I have a postgresql db and a C# application to access it. I'm having a strange error with values I return from a NpgsqlDataAdapter.Fill command into a DataSet.

I've got this code:

NpgsqlCommand n = new NpgsqlCommand();
n.Connection = connector; // a class member NpgsqlConnection

DataSet ds = new DataSet();
DataTable dt = new DataTable();

// DBTablesRef are just constants declared for
// the db table names and columns

ArrayList cols = new ArrayList();
cols.Add(DBTablesRef.all); //all is just *

ArrayList idCol = new ArrayList();
idCol.Add(DBTablesRef.revIssID);

ArrayList idVal = new ArrayList();
idVal.Add(idNum); // a function parameter

// Select builder and Where builder are just small
// functions that return an sql statement based
// on the parameters.  n is passed to the where
// builder because the builder uses named  
// parameters and sets them in the NpgsqlCommand
// passed in
String select = SelectBuilder(DBTablesRef.revTableName, cols) +
WhereBuilder(n,idCol, idVal);

n.CommandText = select;

try
{
    NpgsqlDataAdapter da = new NpgsqlDataAdapter(n);

    ds.Reset();

    // filling DataSet with result from  NpgsqlDataAdapter
    da.Fill(ds);

    // C# DataSet takes multiple tables, but only the first is used here
    dt = ds.Tables[0];
}
catch (Exception e)
{
    Console.WriteLine(e.ToString());
}

So my problem is this: the above code works perfectly, just like I want it to. However, if instead of doing a select on all (*) if I try to name individual columns to return from the query I get the information I asked for, but rather than being split up into seperate entries in the data table I get a string in the first index of the data table that looked something like:

"(0,5,false,Bob Smith,7)"

And the data is correct, I would be expecting 0, then 5, then a boolean, then some text etc. But I would (obviously) prefer it to not be returned as just one big string.

Anyone know why if I do a select on * I get a datatable as expected, but if I do a select on specific columns I get a data table with one entry that is the string of the values I'm asking for?