Question

我需要您的帮助来创建用于更新表中字段的脚本。

在我的应用程序中，我有创建表REQUESTS（表REQUEST）的人（表PERSON）。在过去3年中创建请求的人是活跃的。我已经在表PERSON中创建了一个字段（ACTIVE-默认值：1），以了解此人是否仍在活动。

我创建一个查询以检索每个人的请求数（活动请求，非活动请求）：

select p.ID, p.LASTNAME || ' ' ||  p.FIRSTNAME personName,p.COMPANY, p.ACTIVE,
(SELECT COUNT(*) FROM request req WHERE req.PERSONID = p.ID) AS "NB_REQUEST", 
(SELECT COUNT(*) FROM request reqAct WHERE reqAct.PERSONID = p.ID and reqAct.requestdate > ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_ACTIVE_REQUESTS", 
(SELECT COUNT(*) FROM request reqInact WHERE reqInact.PERSONID = p.ID and reqInact.requestdate < ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_INACTIVE_REQUESTS"
from person p

此脚本正在运行。现在，我想实现一个脚本，用于在人员处于活动状态时更新“活动”字段。我第一次尝试实施IF语句，但是它不起作用。

select p.ID, p.LASTNAME || ' ' ||  p.FIRSTNAME personName,p.COMPANY, p.ACTIVE,
(SELECT COUNT(*) FROM request req WHERE req.PERSONID = p.ID) AS "NB_REQUEST", 
(SELECT COUNT(*) FROM request reqAct WHERE reqAct.PERSONID = p.ID and reqAct.requestdate > ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_ACTIVE_REQUESTS", 
(SELECT COUNT(*) FROM request reqInact WHERE reqInact.PERSONID = p.ID and reqInact.requestdate < ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_INACTIVE_REQUESTS"
(IF((SELECT COUNT(*) FROM request reqReAct WHERE reqAct.PERSONID = p.ID and reqReAct.requestdate > ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36))) > 0 THEN 1 ELSE 0) AS "RE-ACTIVE" 
from person p

您能帮我做到吗？

感谢您的帮助

Answer 1

您可以使用CASE ... END表达式。您可能还想尝试使用EXISTS而不是计数。那可能更快。

SELECT p.id,
       p.lastname || ' ' ||  p.firstname personname,
       p.company,
       p.active,
       (SELECT count(*)
               FROM request req
               WHERE req.personid = p.id) nb_request,
       (SELECT count(*)
               FROM request reqact
               WHERE reqact.personid = p.id
                     AND reqact.requestdate > add_months(trunc(sysdate, 'YYYY'), -36)) nb_active_requests,
       (SELECT count(*)
               FROM request reqinact
               WHERE reqinact.personid = p.id
                     AND reqinact.requestdate < add_months(trunc(sysdate, 'YYYY'), -36)) nb_inactive_requests,
       CASE
         WHEN EXISTS (SELECT *
                             FROM request reqreact
                             WHERE reqact.personid = p.id
                                   AND reqreact.requestdate > add_months(trunc(sysdate, 'YYYY'), -36)) THEN
           1
         ELSE
           0
       END re_active
       FROM person p;

另一种选择是Oracle专有的decode()。

顺便说一句：在比较两个requestdate子查询时，仅使用了<和>运算符。这为=情况留下了空白。也许这不是故意的，您想检查是否对其中之一使用=<或=<。

Answer 2

那么只需将if语句替换为大小写条件

select p.ID,
       p.LASTNAME || ' ' || p.FIRSTNAME personName,
       p.COMPANY,
       p.ACTIVE,
       (SELECT COUNT(*) FROM request req WHERE req.PERSONID = p.ID) AS "NB_REQUEST",
       (SELECT COUNT(*)
          FROM request reqAct
         WHERE reqAct.PERSONID = p.ID
           and reqAct.requestdate > ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_ACTIVE_REQUESTS",
       (SELECT COUNT(*)
          FROM request reqInact
         WHERE reqInact.PERSONID = p.ID
           and reqInact.requestdate <
               ADD_MONTHS(TRUNC(SYSDATE, 'YYYY'), -36)) AS "NB_INACTIVE_REQUESTS",
                             case when ( SELECT COUNT(*)
                                                                                         FROM request reqReAct
                                                                                        WHERE reqAct.PERSONID = p.ID
                                                                                          and reqReAct.requestdate >
                                                                                              ADD_MONTHS(TRUNC(SYSDATE,
                                                                                                               'YYYY'),
                                                                                                         -36))) >0 THEN 1 ELSE 0 end ) AS "RE-ACTIVE"


  from person p

带有IF语句的脚本，用于更新Oracle表字段

2 个答案: