Random musings - Group by

Edwin Kurian on Wed Feb 18, 2009 7:22 am

Is the Group by clause in a Select statement redundant? Why is it even needed?
Hoping to get your thoughts.

Edwin

BoxesAndLines on Wed Feb 18, 2009 10:27 am

Because the DBMS requires it.

Edwin Kurian on Wed Feb 18, 2009 2:03 pm

That is what I am trying to understand...Why does the DBMS need it.
Logically if any columns are aggrergated, shouldn't the SQL group by the other columns?
Is there a case where some columns are aggregated, and some of the other columns are not part of the group by?

slaborda on Wed Feb 18, 2009 2:46 pm

It depends on database engine.

Please search in google info about "over partition" clause.
With this you can combine aggregated data with detail data.

Sergi

Random musings - Group by

Random musings - Group by

Re: Random musings - Group by

Re: Random musings - Group by

Over partition