我认为这样比较好:

SELECT * FROM "comments" WHERE ("comments"."id" IN (1,3,2,4))
    ORDER BY  id=1 DESC, id=3 DESC, id=2 DESC, id=4 DESC

在Postgresql:

select *
from comments
where id in (1,3,2,4)
order by position(id::text in '1,3,2,4')

SELECT * FROM "comments" JOIN (
  SELECT 1 as "id",1 as "order" UNION ALL 
  SELECT 3,2 UNION ALL SELECT 2,3 UNION ALL SELECT 4,4
) j ON "comments"."id" = j."id" ORDER BY j.ORDER

或者如果你喜欢恶而不是善:

SELECT * FROM "comments" WHERE ("comments"."id" IN (1,3,2,4))
ORDER BY POSITION(','+"comments"."id"+',' IN ',1,3,2,4,')

select * from comments where comments.id in 
(select unnest(ids) from bbs where id=19795) 
order by array_position((select ids from bbs where id=19795),comments.id)

这里，[bbs]是主表，它有一个名为ids的字段， id是存储注释的数组。id。

在postgresql 9.6中通过

你可以很容易地使用(在PostgreSQL 8.2中引入)VALUES()，()。

语法是这样的:

select c.*
from comments c
join (
  values
    (1,1),
    (3,2),
    (2,3),
    (4,4)
) as x (id, ordering) on c.id = x.id
order by x.ordering

相比使用序列的版本略有改进，我认为:

CREATE OR REPLACE FUNCTION in_sort(anyarray, out id anyelement, out ordinal int)
LANGUAGE SQL AS
$$
    SELECT $1[i], i FROM generate_series(array_lower($1,1),array_upper($1,1)) i;
$$;

SELECT 
    * 
FROM 
    comments c
    INNER JOIN (SELECT * FROM in_sort(ARRAY[1,3,2,4])) AS in_sort
        USING (id)
ORDER BY in_sort.ordinal;