Re: [SQL] nulls and datetime

> > I have a table with datetime fields, some of which are null. I'm
> > trying to extract the date and time components with the date() and
> > time() functions but the null values break these functions.
> regression=> SELECT t1, date(d1) from test1;
> ERROR: Unable to convert null datetime to date
> This is undesirable, I agree. It seems to me that those routines should
> just return NULL given NULL input, rather than going out of their way to
> break applications. Thomas, can you defend this behavior?

No, other than this is the first time I've ever seen that code execute
;)

In previous versions, single-argument functions with NULL input were
short-circuited in fmgr (??) and never actually were called. I put in
this code just as a guard.

Seems to me that NULL in should produce NULL out, which was the old
behavior. I'll add this to my ToDo, unless someone else has already
picked it up.

- Thomas

--
Thomas Lockhart lockhart(at)alumni(dot)caltech(dot)edu
South Pasadena, California