Re: bit|varbit #, xor operator
От | David G. Johnston |
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Тема | Re: bit|varbit #, xor operator |
Дата | |
Msg-id | CAKFQuwYC47oFZLO4Q0c2K7zbW86_Tc3n1s53ADV2DqGhFA=WhQ@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: bit|varbit #, xor operator (Jim Nasby <Jim.Nasby@BlueTreble.com>) |
Список | pgsql-hackers |
On 10/17/16 11:29 AM, Tom Lane wrote:Jim Nasby <Jim.Nasby@bluetreble.com> writes:On 10/16/16 3:13 PM, Tom Lane wrote:Related to this I'd also like to add a boolean XOR operator as that's a
relatively common request/question.We have boolean XOR; it's spelled "<>".I always forget about that...
Maybe it should be mentioned explicitly in the docs.
Hrm, went to go add it and it appears we don't have a section for boolean type operators. I guess I should add it to 9.1?
There are no symbolic operators, just the standard SQL keywords: AND, OR, NOT.
Adding a note there pertaining to XOR should be sufficient.
though, it doesn't work for boolean arrays.
Define doesn't work?
I would expect array[true, false] XOR array[true, true] to return array[false, true], but <> just returns a single true (since the arrays are !=).
Though, I guess what would make the most sense there is a map function that would apply an operator or function to every element of a set of arrays. But I don't see any way to do that without major changes to how anyarray works.
Yeah, your expectations seem off here given that:
SELECT array[true, false]::boolean[] AND array[true, true]::boolean[]
is invalid...
David J.
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