provide method rows() and firstRow() on groovy.sql.DataSet

Added two patches for the proposed enhancement to the DataSet class. I have added the rows() method
and the firstRow() method. I have also updated the SqlCompleteTest class to test these two methods.

However, I do have a question on this open improvement. The way I read the "improvement" is that the rows() method
will return all of the rows on the underlying tableset. To implement this I simply did a SELECT * FROM the table to
build the data. However, what happens if the user is trying to filter based on a where. Shouldn't the call really return all of the rows for the DataSet.

Please let me know how exactly this code should work. I can change the code to behave whatever way needed.

Came to the realization that I could just re-use the rows() method on the SQL class and just pass in a SQL
string. D**mba@@ to go and cut-and paste code. I uploaded the revised dataset class. The changes still work and the unit tests pass.

implemented

I think John Carnell's query is an important one here:

"... However, what happens if the user is trying to filter based on a where. Shouldn't the call really return all of the rows for the DataSet."

I think the answer to this is yes.

Here is some code:

def athletes = [
    [firstname: 'Paul', lastname:'Tergat', dateOfBirth:'1969-06-17'],
    [firstname: 'Khalid', lastname:'Khannouchi', dateOfBirth:'1971-12-22'],
    [firstname: 'Ronaldo', lastname:'da Costa', dateOfBirth:'1970-06-07'],
    [firstname: 'Paula', lastname:'Radcliffe', dateOfBirth:'1973-12-17']
]

athleteSet = db.dataSet('Athlete')
athletes.each { a -> athleteSet.add(a) }
youngsters = athleteSet.findAll{ it.dateOfBirth > '1970-1-1'}
def rows = []
youngsters.each { rows += it.lastname }
println rows.join(', ')           // => Khannouchi, da Costa, Radcliffe
println youngsters.rows().size()  // => 4

I would expect rows() for youngsters to return the three youngster rows not the entire original table (4 rows here).

do I see it right, that we just need to replace

    public List rows() throws SQLException {
        String sql  = "SELECT * FROM " + table;
        return rows(sql);

    }

with

    public List rows() throws SQLException {
        String sql  = getSql();
        return rows(sql);
    }

in DataSet?

Fixed

Thought you would have already clocked off, so went ahead and fixed it.

Yes, your suggestion was almost what I did - just:

rows(getSql(), getParameters())

because sql is stored proc with params.