बड़ी या अपरिभाषित श्रेणियों के साथ क्रॉसस्टैब

create table vote (Photo integer, Voter text, Decision text);
insert into vote values
(1, 'Alex', 'Cat'),
(1, 'Bob', 'Dog'),
(1, 'Carol', 'Cat'),
(1, 'Dave', 'Cat'),
(1, 'Ed', 'Cat'),
(2, 'Alex', 'Cat'),
(2, 'Bob', 'Dog'),
(2, 'Carol', 'Cat'),
(2, 'Dave', 'Cat'),
(2, 'Ed', 'Dog'),
(3, 'Alex', 'Horse'),
(3, 'Bob', 'Horse'),
(3, 'Carol', 'Dog'),
(3, 'Dave', 'Horse'),
(3, 'Ed', 'Horse'),
(4, 'Alex', 'Horse'),
(4, 'Bob', 'Horse'),
(4, 'Carol', 'Cat'),
(4, 'Dave', 'Horse'),
(4, 'Ed', 'Horse'),
(5, 'Alex', 'Dog'),
(5, 'Bob', 'Cat'),
(5, 'Carol', 'Cat'),
(5, 'Dave', 'Cat'),
(5, 'Ed', 'Cat')
;

बिल्ली के लिए क्वेरी:

select photo,
    alex + bob + carol + dave + ed as Total,
    alex, bob, carol, dave, ed
from crosstab($$
    select
        photo, voter,
        case decision when 'Cat' then 1 else 0 end
    from vote
    order by photo
    $$,'
    select distinct voter
    from vote
    order by voter
    '
) as (
    photo integer,
    Alex integer,
    Bob integer,
    Carol integer,
    Dave integer,
    Ed integer
);
 photo | total | alex | bob | carol | dave | ed 
-------+-------+------+-----+-------+------+----
     1 |     4 |    1 |   0 |     1 |    1 |  1
     2 |     3 |    1 |   0 |     1 |    1 |  0
     3 |     0 |    0 |   0 |     0 |    0 |  0
     4 |     1 |    0 |   0 |     1 |    0 |  0
     5 |     4 |    0 |   1 |     1 |    1 |  1

यदि मतदाताओं की संख्या बड़ी है या ज्ञात नहीं है तो इसे गतिशील रूप से किया जा सकता है:

do $do$
declare
voter_list text;
r record;
begin

drop table if exists pivot;

voter_list := (
    select string_agg(distinct voter, ' ' order by voter) from vote
    );

execute(format('
    create table pivot (
        decision text,
        photo integer,
        Total integer,
        %1$s
    )', (replace(voter_list, ' ', ' integer, ') || ' integer')
));

for r in
select distinct decision from vote
loop
    execute (format($f$
        insert into pivot
        select
            %3$L as decision,
            photo,
            %1$s as Total,
            %2$s
        from crosstab($ct$
            select
                photo, voter,
                case decision when %3$L then 1 else 0 end
            from vote
            order by photo
            $ct$,$ct$
            select distinct voter
            from vote
            order by voter
            $ct$
        ) as (
            photo integer,
            %4$s
        );$f$,
        replace(voter_list, ' ', ' + '),
        replace(voter_list, ' ', ', '),
        r.decision,
        replace(voter_list, ' ', ' integer, ') || ' integer'
    ));
end loop;
end; $do$;

उपरोक्त कोड ने सभी निर्णयों के साथ टेबल पिवट बनाया:

select * from pivot where decision = 'Cat';