SQL 查询获取某个状态的最大日期并从另一个状态的最大日期中减去该最大日期

Question

一个例子是..假设工单处于新状态。我想获取新状态的最大日期和完成状态的最大日期，并计算最大完成状态与最大新状态之间的差异

例如。

SELECT t.ID,
       MAX(update_date) WHERE t.status = 'New' start_time,
       MAX(update_date) WHERE t.status = 'Completed' stop_time,
DATEDIFF(second, MAX(update_date), MAX(update_date)) elapsed_sec
FROM xxx.dbo t
GROUP BY t.ID;

非常感谢，

P

Answer 1

SELECT
    t.id
    ,DATEDIFF(second, start_time, stop_time) elapsed_sec
FROM (
    SELECT
        ID,
        (SELECT MAX(update_date) from xxx.dbo WHERE status = 'New' AND ID=t2.ID) start_time,
        (SELECT MAX(update_date) from xxx.dbo WHERE status = 'Completed' AND ID=t2.ID) stop_time
    FROM xxx.dbo t2
) t

Answer 2

我建议使用条件聚合而不是相关子查询来执行此操作：

SELECT t.ID,
       MAX(CASE WHEN t.status = 'New' THEN update_date END) as start_time,
       MAX(CASE WHEN t.status = 'Completed' THEN update_date END) as stop_time,
       MAX(update_date) WHERE t.status = 'Completed' stop_time,
       DATEDIFF(second,
                MAX(CASE WHEN t.status = 'New' THEN update_date END),
                MAX(CASE WHEN t.status = 'Completed' THEN update_date END)
               ) as elapsed_sec
FROM xxx.dbo t
GROUP BY t.ID;

SQL 查询获取某个状态的最大日期并从另一个状态的最大日期中减去该最大日期

SQL Query to get the Max Date of a certain Status and subract that from the Max Date of another Status

sql

sql-server

datetime

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