Pollard, Mike schrieb:
Richard Huxton wrote:
Pollard, Mike wrote:
Firstly, if you just want a count, what's wrong with count(1) or
count(*).
Because unless the column does not allow nulls, they will not return
the
same value.
Ah, but in the example given the column was being matched against a
value, so nulls were already excluded.
--
Details, details. But there is a valid general question here, and
changing the semantics of the query will not address it. When doing a
count(col), why convert col into a string just so you can determine if
it is null or not? This isn't a problem on a small amount of data, but
Why convert? A null is always null no matter in which datatype.
it seems like a waste, especially if you are counting millions of
records. Is there some way to convert this to have the caller convert
nulls to zero and non-nulls to 1, and then just pass an int? So
logically the backend does:
Select count(case <col> when null then 0 else 1) from <table>
Which would be totally silly :-) no matter if its 0 or 1
it counts as 1. Do you mean sum() maybe?
Even then you dont need coalesce to convert null to 0
because sum() just ignores null.
And count just adds the number to the running tally.
Which number here?
Mike Pollard
SUPRA Server SQL Engineering and Support
strange...
Cincom Systems, Inc.
---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly
