PostgreSQL 检查数组是否包含左侧数组中的任何元素
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PostgreSQL check if array contains any element from left-hand array
提问by Lander
I know that in PostgreSQL you can run a query like:
我知道在 PostgreSQL 中你可以运行如下查询：
SELECT (1 = ANY('{1,3,4,7}'::int[])) AS resultto check if the right-hand array contains the element 1. I was wondering if there is an easy way to check if the right-hand array contains any element from the left-handarray. Something like:
SELECT (1 = ANY('{1,3,4,7}'::int[])) AS result检查右侧数组是否包含元素1。我想知道是否有一种简单的方法可以检查右侧数组是否包含左侧数组中的任何元素。就像是：
SELECT ('{2,3}'::int[] = ANY('{1,3,4,7}'::int[])) AS result
SELECT ('{2,3}'::int[] = ANY('{1,3,4,7}'::int[])) AS result
Is there an easy way to do this without iterating over the left-hand loop myself?
有没有一种简单的方法可以做到这一点而无需自己迭代左侧循环？
回答by Craig Ringer
Sure, use the &&array-overlaps operator:
当然，使用&&数组重叠运算符：
SELECT ARRAY[1,2] && ARRAY[1,3,4,7];
See array functions and operators.
请参阅数组函数和运算符。
回答by Daniel Sparing
Assuming that your inputs are arrays but it is okay to unwrap them using unnest(), here is a solution:
假设您的输入是数组，但可以使用 展开它们unnest()，这是一个解决方案：
SELECT count(*)>0
FROM
(SELECT unnest('{2,3}'::int[]) a1) t1
join (SELECT unnest('{1,3,4,7}'::int[]) a2) t2
on t1.a1=t2.a2;
