sql - 如何获取两个日期戳之间的时间差并按降序排列

Question

我需要以小时为单位的两个日期戳之间的时差，并且需要按降序排列它们以获得中位数

SELECT "fulfillmentshistories"."fulfillmentid" as "Fulfillment ID" FROM FULFILLMENTHISTORIES
WHERE (Fulfillments."status" IN ('paid','delivered') AND (DATE("fulfillmenthistories"."createdAt") BETWEEN DATE('{{startDate}}') AND DATE('{{endDate}}')))
union
SELECT DATEDIFF(HOUR,   'startDate'-'endDate') as DATEDIFF;
ORDER BY DATEDIFF, DESC

这是我试过的请帮忙

SELECT "fulfillmentshistories"."fulfillmentid" as "Fulfillment ID" FROM    FULFILLMENTHISTORIES
WHERE (Fulfillments."status" IN ('paid','delivered') AND (DATE ("fulfillmenthistories"."createdAt") BETWEEN DATE('{{startDate}}') AND DATE('{{endDate}}')))
union
SELECT DATEDIFF(HOUR,   'startDate'-'endDate') as DATEDIFF;
ORDER BY DATEDIFF, DESC

运行查询时出错：“ORDER”第 5 行或附近的语法错误：ORDER BY DATEDIFF, DESC ^

Answer 1

SELECT DATEDIFF(HOUR, 'startDate'-'endDate') as DATEDIFF; ORDER BY DATEDIFF, DESC

应该

SELECT DATEDIFF(HOUR, 'startDate'-'endDate') as DATEDIFF ORDER BY DATEDIFF, DESC ;

并尝试避免使用类似于函数名的别名。

Answer 2

UNION
SELECT DATEDIFF(HOUR,   'startDate'-'endDate') as DATEDIFF;
ORDER BY DATEDIFF, DESC

应该

UNION
SELECT DATEDIFF(HOUR,   'startDate'-'endDate') as DATEDIFF
ORDER BY DATEDIFF DESC;

删除 DATEDIFF 后的分号和 ORDER BY DATEDIFF 后的逗号。分号应该出现在 SQL 语句的末尾，因为整个是一个 sql 语句。