取两个日期之间的最小值时出错

Question

DROP TABLE IF EXISTS tmp1_variables;
CREATE TEMPORARY TABLE tmp1_variables AS (
SELECT
    '2016-10-29'::date as start_date,
'2017-01-28'::date as end_date2,
dateadd(day,-13,getdate())::date as end_date);


SELECT cobrand_id, sum(calc) AS a, sum(count) AS b FROM jwn_calc s, tmp1_variables
        where s.optimized_transaction_date > start_date
AND s.optimized_transaction_date <= min(end_date,end_date2) 

我特别在min(end_date,end_date2)，出现错误：

[42883] 错误：函数 min(date, date) 不存在 提示：没有函数匹配给定的名称和参数类型。您可能需要添加显式类型转换。

Answer 1

使用LEAST()代替MIN()：

SELECT cobrand_id,
       SUM(calc) AS a,
       SUM(count) AS b
FROM jwn_calc s
INNER JOIN tmp1_variables t
    ON s.optimized_transaction_date > t.start_date AND
       s.optimized_transaction_date <= LEAST(t.end_date, t.end_date2)

请注意，我已将您的隐式连接替换为显式INNER JOIN. 作为一般规则，您应该避免在FROM子句中使用逗号。

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