The 'data integrity' rule for database I'm designing says that any
subject we're tracking (persons, companies, whatever) is assigned an
agreement that can be in several states: 'Approved', 'Unapproved' or
'Obsolete'. One subject can have only one (or none) 'Approved' or
'Unapproved' agreement, and
On 2010-04-19, Mario Splivalo wrote:
> The 'data integrity' rule for database I'm designing says that any
> subject we're tracking (persons, companies, whatever) is assigned an
> agreement that can be in several states: 'Approved', 'Unapproved' or
> 'Obsolete'. One subject can have only one (or no
Jasen Betts wrote:
> ...
>
>> The 'proper' way to do this (as suggested by earlier posts on this
>> mailing list) is to use partial UNIQUE indexes, but I have problem with
>> that too: indexes are not part of DDL (no matter that primary key
>> constraints and/or unique constraints use indexes to e
Jasen Betts writes:
> On 2010-04-19, Mario Splivalo wrote:
>> The 'proper' way to do this (as suggested by earlier posts on this
>> mailing list) is to use partial UNIQUE indexes, but I have problem with
>> that too: indexes are not part of DDL (no matter that primary key
>> constraints and/or un
