On Mon, May 30, 2022 at 09:35:15PM +0000, John Rouillard wrote:
> 
> Also this is documented in customizing.txt:
> 
>    Note that if an "order" property is defined on a Class that is used for
>    sorting, all items of that Class *must* have a value against the "order"
>    property, or sorting will result in random ordering.
> 
> Is this still valid for items without a valid order property?

Hmm, I don't think this has ever been valid but looking through the
tests I'm not so sure. We *do* test for Link values being NULL on
sorting and generate complicated SQL for postgresql to match the default
sort order of NULL values of mysql (it sorts NULL values *last*).
But I'm not sure we do the same for non-Link properties. So maybe we
create an issue on this to investigate. It may well be that the
different SQL backends behave differently:

The python2 postgresql backend sorts NULL values in order attributes
*first* (in the index view of a class) and python3 behaviour hasn't
changed. So it might well be that postgres sorts NULL first while mysql
sorts NULL last and the above statement comes from that observation.  I
still find "NULL first" the more intuitive behaviour.

Ralf
-- 
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