At 04:33 AM 28/02/2010, you wrote:

>Hello all
>
>Is there a list of datatypes that are not comparable in COALESCE?
>
>'Date' is probably one of them...

That is a "dark" question, Marcin! ;-) What are you trying to do with COALESCE?

You cannot compare anything with NULL, but you can compare a date with a date, i.e., this is OK:

select
....,
coalesce (MyDate, CURRENT_DATE) as SomeDate,
....

And SomeDate will be returned as a DATE field. If MyDate is NULL, then SomeDate will be today's date.

The usual rules apply for data type compatibility and use of literals, so the following would not be valid:

select
....,
coalesce (MyDate, 'today') as SomeDate,

You would have to cast the literal:

select
....,
coalesce (MyDate, (cast('today' as DATE))) as SomeDate,

Better that you provide an example of the usage of COALESCE that doesn't work for you so we can figure out why.

./heLen