Postgresql：添加到 CASE

Question

我在 Postgresql 中有这段代码：

CASE 
    WHEN a > b THEN 'a is bigger than b'
    WHEN a > c THEN 'a is bigger than c'
    ELSE ' '
END AS "all bigs",

现在的问题是我需要添加两个 WHEN 的组合，这样第二个 WHEN 就可以了不删除第一个。

我的专栏应该看起来像 (a is bigger than b\na is bigger than c):

all bigs
---------
a is bigger than a
a is bigger than c

不喜欢：

all bigs
---------
a is bigger than c

如何操作？

@zedfoxus，尝试这个，但没有成功 ("ERROR: syntax error at or near "UNION""):

CASE 
    WHEN a > b THEN 'a is bigger than b'::text
UNION ALL
    WHEN a > c THEN 'a is bigger than c'::text
END AS "all bigs"

Answer 1

试试这个：

create table test (a int, b int, c int);
insert into test values (3, 2, 1);

select case when a > b then 'a is bigger than b' else '' end as "all bigs" from test
union all
select case when a > c then 'a is bigger than c' else '' end as "all bigs" from test

Postgresql：添加到 CASE

Postgresql: add to CASE

postgresql

case