how to choose first row when use group by in web2py

Question

I have a table in db. and when i use this code

results = db().select(db.project.ALL, orderby=db.project.id, groupby=db.project.status)

I can only choose the last row in repeats. how could i choose the first one?

Answer 1

The select() method will return a Rows object, which is a itterable collection of Row objects. The order of which rows will apear in your results variable will vary depending on your orderby parameter passed to your select() method. If you simply want to get a single record, which is the first one out of your select(), you could change the above code to:

results = db().select(db.project.ALL, orderby=db.project.id, groupby=db.project.status).first()

But if your intent is to reverse the order of which you're getting the rows in result, add the tilde operator (~) to your orderby parameter, which will result in adding a ORDER BY ____ DESC in relational databases. Eg:

results = db().select(db.project.ALL, orderby=~db.project.id, groupby=db.project.status)