我有一个CTE,它有一个数组列,并希望通过该id数组过滤另一列。
with vars as (
select
(1, 7, 10000) bubble_ids,
'Frank' name
)
select * from walruses
inner join tusks on walruses.id = tusks.walrus_id
where (
name = (select name from vars)
and tusks.bubble_id IN (select bubble_ids from vars)
);
这会产生以下内容:ERROR: operator does not exist: integer = record
我尝试过取消测试——unnest(bubble_ids)
——这会导致ERROR: record type has not been registered
做这件事的正确方法是什么?
(1, 7, 10000)
不定义数组。这是一个行构造函数,它创建一个匿名记录(有三个字段(。
数组文字是用方括号写的,并且必须以关键字array
为前缀,例如array[1, 7, 10000]
。或者,您可以将其写为字符串值:'{1,7,1000}'
当使用CTE作为变量/参数的"容器"时,我通常使用交叉连接使其可用于查询。这是较少键入
with vars as (
select
array[1, 7, 10000] bubble_ids,
'Frank' as name --<< you need the AS, because name is a keywod
)
select *
from walruses
inner join tusks on walruses.id = tusks.walrus_id
cross join vars v
where name = v.vars
and tusks.bubble_id = any(v.bubble_ids);
我更喜欢values
子句而不是select
来定义常数值。
with vars(bubble_ids, name) as (
values (array[1, 7, 10000], 'Frank')
)
select *
from walruses
inner join tusks on walruses.id = tusks.walrus_id
cross join vars v
where name = v.vars
and tusks.bubble_id = any(v.bubble_ids);