On Thursday 04 December 2003 12:51, kverens wrote:
> I have a line of SQL which I thought was simple:
> update photographers set state=town where state is null and
>> this returns 0 changes.
>> strangely, the below returns 187 results:
> select * from photographers where state is null and country='Ireland';
>> town is plain text, as is state and country.
select count(* ) from photographers where state is null and town is null and
update photographers set state=town where state is null and country='Ireland';
will return 0 changes if town is already null for all the matching rows.
Of course, I could be missing something glaring. SQL's handling of null has a
high tripup factor.
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