Re: [HACKERS] plpgsql doesn't coerce boolean expressions to boolean

Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
> ERROR is the cleanest way, but I'd vote for conversion to boolean to
> keep the damage within reason.

Which style of conversion did you like? These were the choices:

>> 3. Try to convert nonbooleans to boolean using plpgsql's usual method
>> for cross-type coercion, ie run the type's output proc to get a
>> string and feed it to bool's input proc. (This seems unlikely to
>> avoid throwing an error in very many cases, but it'd be the most
>> consistent with other parts of plpgsql.)
>>
>> 4. Use the parser's coerce_to_boolean procedure, so that nonbooleans
>> will be accepted in exactly the same cases where they'd be accepted
>> in a boolean-requiring SQL construct (such as CASE). (By default,
>> none are, so this isn't really different from #2. But people could
>> create casts to boolean to override this behavior in a controlled
>> fashion.)

At this point I'm kinda leaning to #4, because (for example) people
could create a cast from integer to boolean to avoid having to fix their
plpgsql functions right away. #3 would not offer any configurability of
behavior.

regards, tom lane