Question

有人可以更改以下查询以使用postgres吗？

SELECT
user2.id AS ID,
ul.timeaccess,
user2.firstname AS Firstname,
user2.lastname AS Lastname,
user2.email AS Email,
user2.username AS IDNumber,
user2.institution AS Institution,

IF (user2.lastaccess = 0,'never',
DATE_FORMAT(FROM_UNIXTIME(user2.lastaccess),'%Y-%m-%d')) AS dLastAccess

,(SELECT DATE_FORMAT(FROM_UNIXTIME(timeaccess),'%Y-%m-%d') FROM      mdl_user_lastaccess WHERE userid=user2.id AND courseid=c.id) AS CourseLastAccess

,(SELECT r.name
FROM  mdl_user_enrolments AS uenrol
JOIN mdl_enrol AS e ON e.id = uenrol.enrolid
JOIN mdl_role AS r ON e.id = r.id
WHERE uenrol.userid=user2.id AND e.courseid = c.id) AS RoleName

FROM mdl_user_enrolments AS ue
JOIN mdl_enrol AS e ON e.id = ue.enrolid
JOIN mdl_course AS c ON c.id = e.courseid
JOIN mdl_user AS user2 ON user2 .id = ue.userid
LEFT JOIN mdl_user_lastaccess AS ul ON ul.userid = user2.id
WHERE c.id=14 AND ue.userid NOT IN (SELECT qa.userid FROM mdl_quiz_attempts     AS qa
JOIN mdl_quiz AS q ON qa.quiz = q.id
JOIN mdl_course AS c ON q.course = c.id
WHERE c.id = 14 AND q.name LIKE '%quiz name goes here%')

是Moodle的我知道它必须去to_char等，但不知道如何改变它

提前致谢

Answer 1

在Postgres文档上查看：Data Type Formatting Functions。

使用to_char（日期，＆＃39; YYYY-MM-DD＆＃39;）

例如：

select to_char('20170501'::date, 'YYYY-MM-DD')

返回：

2017-05-01

在此处查看：http://rextester.com/JDZA16474

Answer 2

SELECT
user2.id AS "ID",
ul.timeaccess,
user2.firstname AS "Firstname",
user2.lastname AS "Lastname",
user2.email AS "Email",
user2.username AS "IDNumber",
user2.institution AS "Institution",

(CASE WHEN user2.lastaccess = 0 THEN'never' END ||
to_char(to_timestamp(user2.lastaccess)::date,'YYYY-MM-DD')) AS "dLastAccess"

,(SELECT to_char(to_timestamp(timeaccess)::date,'YYYY-MM-DD') FROM      mdl_user_lastaccess WHERE userid=user2.id AND courseid=c.id) AS "CourseLastAccess"

,(SELECT r.name
FROM  mdl_user_enrolments AS uenrol
JOIN mdl_enrol AS e ON e.id = uenrol.enrolid
JOIN mdl_role AS r ON e.id = r.id
WHERE uenrol.userid=user2.id AND e.courseid = c.id) AS "RoleName"

FROM mdl_user_enrolments AS ue
JOIN mdl_enrol AS e ON e.id = ue.enrolid
JOIN mdl_course AS c ON c.id = e.courseid
JOIN mdl_user AS user2 ON user2 .id = ue.userid
LEFT JOIN mdl_user_lastaccess AS ul ON ul.userid = user2.id
WHERE c.id=14 AND ue.userid NOT IN (SELECT qa.userid FROM mdl_quiz_attempts     AS qa
JOIN mdl_quiz AS q ON qa.quiz = q.id
JOIN mdl_course AS c ON q.course = c.id
WHERE c.id = 14 AND q.name LIKE '%quiz name goes here%')

嘿，我试过了。

FROM_UNIXTIME - 相当于postgres上的to_timestamp。在postgres中 IF ELSE CASE WHEN 。 to_char - 如果您想格式化日期，请使用此功能。

将SQL DATEFORMAT转换为Postgres

2 个答案: