签署日期后的前三个月

Question

我有列id, signed_date, begin_date，并有以下查询：

select id, signed_date, count(*)
FROM table t1
WHERE   is_ever = 'true'
AND   signed_date >= '2021-01-01'
group by id, signed_date

我需要从signed_date到或在前三个月内延迟。

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如果在DB中有begin_date，则自启动延迟时起。不能使用CTE

Answer 1

区间函数应该有帮助：

select id, signed_date, count(*)
FROM table t1
WHERE   is_ever = 'true'
AND   signed_date = '2021-01-01' and begin_date between signed_date AND signed_date + interval '3 months'
group by id, signed_date