我正在使用SQLPLUS,并且确实需要能够使用IF/THEN/ELSE
,但我一直无法找到任何有关如何使其工作的信息。 (消息来源都说它不能完成),所以我试图用CASE
来做同样的事情。我需要查看sysdate,如果它位于日期A和日期B之间,则运行Select语句。如果它没有转到下一个CASE
声明。这里是我想要做的事情的一个窍门:sqlplus select case case
CASE
WHEN sysdate BETWEEN TO_DATE('28/08/2016', 'DD/MM/YYYY') AND TO_DATE('20/11/2016', 'DD/MM/YYYY')
THEN
(SELECT
schools.abbreviation,
students.entrydate,
students.lastfirst as Student,
students.student_number,
students.grade_level,
courses.course_name,
teachers.lastfirst as Teacher,
pgfinalgrades.grade,
round(pgfinalgrades.percent) as Percent,
(CASE
WHEN ps_customfields.getcf('Students', students.ID, 'zz_B_Soccer') = '1'
THEN 'Boys_Soccer'
ELSE NULL
END) AS "Athletic Sport - Fall"
FROM pgfinalgrades
JOIN sections on pgfinalgrades.sectionid = sections.id
JOIN courses on upper(sections.course_number) = upper(courses.course_number)
JOIN cc on pgfinalgrades.studentid = cc.studentid and sections.id = cc.sectionid and sysdate between cc.dateenrolled and cc.dateleft
JOIN students on pgfinalgrades.studentid = students.id
JOIN prefs on prefs.name = 'curfgname-S' || sections.schoolid and pgfinalgrades.finalgradename = to_char(substr(prefs.value, 1,2))
JOIN terms on terms.schoolid = sections.schoolid and sysdate between terms.firstday and terms.lastday and terms.isyearrec = 1
JOIN schools on sections.schoolid = schools.school_number
JOIN teachers on sections.teacher = teachers.id
WHERE students.enroll_status = 0
AND sysdate between cc.dateenrolled and cc.dateleft
AND (pgfinalgrades.grade = 'C-'
OR pgfinalgrades.grade = 'D'
OR pgfinalgrades.grade = 'D-'
OR pgfinalgrades.grade = 'E'
OR pgfinalgrades.grade = 'F'
)
AND --Fall Sports
( ps_customfields.getcf('Students', students.ID, 'zz_B_Soccer') IS NOT NULL
OR ps_customfields.getcf('Students', students.ID, 'zz_B_Cross_Country') IS NOT NULL
OR ps_customfields.getcf('Students', students.ID, 'zz_Golf') IS NOT NULL
));
接下来将是冬季运动,然后是春季运动。 我在sysdate行收到错误“unknown command”,然后运行每个case。我不知道如何让它抓住今天的日期,确定它属于哪种情况,然后运行那一个让我输出。我打算在整个学年期间将其自动化为每周运行一次,并且不希望每年都要触碰它一次以上。 如果任何人都可以想到更好的方式来做到这一点,我是全部耳朵。 :)
这并不是说我清楚你需要做什么。尝试构建一个简单的示例(一个包含一些有意义的数据的示例表)来解释您需要执行的操作。您可能还想看看[mcve] – Aleksej
不,“CASE”不是流控制构造,主要是因为SQL是查询语言而不是编程语言。您当然可以使用PL/SQL,但是,我不会在PL/SQL中编写整个应用程序。说,我怀疑你可以用标准的SQL来获得你的结果,但是我们当然对你的问题一无所知。 –
另请注意,您无法为每个CASE语句选择不同数量的列。相反,您需要使用返回标量(或对象类型)的子查询选择,例如:当dummy ='X'时选择case(从all_users中选择count(*))else(从double中选择count(*))end来自双重的cnt;或者选择dummy ='X'的情况,然后(从rownum = 1的all_users中选择myType(user_id,created))else(从dual中选择myType(111,sysdate))从dual结束; – gregory