Re: group by rollup and cube

From: Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
To: john snow <ofbizfanster(at)gmail(dot)com>, pgsql-novice(at)postgresql(dot)org
Subject: Re: group by rollup and cube
Date: 2017-11-16 07:27:27
Message-ID: 1510817247.2639.20.camel@cybertec.at
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-novice

john snow wrote:
> i'm trying to learn how to do these from these examples that i found in:
>
> https://www.databasejournal.com/features/mssql/using-the-rollup-cube-and-grouping-sets-operators.html
>
> after modifying the code to run in postgresql 10, i'm finding that even though
> i'm getting subtotal and grand total values same as those in the article,
> i'm not quite getting the report rows in the desired orders.

A query result has no guaranteed ordering unless you specify
one with an ORDER BY clause.

ORDER BY is executed after the grouping, so you can use it to
sort the result rows.

You'll have to come up with an ORDER BY clause that puts the
result in the desired order.

The NULLS LAST clause will help in some of your cases.
For example, for your first question I'd use

ORDER BY type NULLS LAST

to put the summary line at the bottom.

Yours,
Laurenz Albe

In response to

Browse pgsql-novice by date

  From Date Subject
Next Message Dean Montgomery 2017-11-17 22:52:54 ERROR: expected one dependency record for TOAST table, found 0
Previous Message Laurenz Albe 2017-11-16 07:21:09 Re: How to get n records from parent table and their children