Sql 使用Oracle将三个表与PIVOT合并为一个表
我有三个Oracle SQL select查询,它们返回以下结果。 第一次选择查询返回结果:Sql 使用Oracle将三个表与PIVOT合并为一个表,sql,oracle,Sql,Oracle,我有三个Oracle SQL select查询,它们返回以下结果。 第一次选择查询返回结果: user_id | user_name | ---------|-----------| 1 | user_1 | 2 | user_2 | 3 | user_3 | 4 | user_4 | exam_id | exam_name | ---------|-----------| 1 | exam_
user_id | user_name |
---------|-----------|
1 | user_1 |
2 | user_2 |
3 | user_3 |
4 | user_4 |
exam_id | exam_name |
---------|-----------|
1 | exam_1 |
2 | exam_2 |
3 | exam_3 |
exam_id | user_id | exam_date |
---------|---------|-----------|
1 | 1 | 2017 |
1 | 2 | 2018 |
1 | 3 | 2017 |
2 | 3 | 2018 |
第二个select查询返回结果:
user_id | user_name |
---------|-----------|
1 | user_1 |
2 | user_2 |
3 | user_3 |
4 | user_4 |
exam_id | exam_name |
---------|-----------|
1 | exam_1 |
2 | exam_2 |
3 | exam_3 |
exam_id | user_id | exam_date |
---------|---------|-----------|
1 | 1 | 2017 |
1 | 2 | 2018 |
1 | 3 | 2017 |
2 | 3 | 2018 |
第三个select查询返回结果:
user_id | user_name |
---------|-----------|
1 | user_1 |
2 | user_2 |
3 | user_3 |
4 | user_4 |
exam_id | exam_name |
---------|-----------|
1 | exam_1 |
2 | exam_2 |
3 | exam_3 |
exam_id | user_id | exam_date |
---------|---------|-----------|
1 | 1 | 2017 |
1 | 2 | 2018 |
1 | 3 | 2017 |
2 | 3 | 2018 |
我希望将这些查询合并以获得结果:
user_id | user_name | exam_1 | exam_2 | exam_3 |
---------|-----------|--------|--------|--------|
1 | user_1 | 2017 | | |
2 | user_2 | 2018 | | |
3 | user_3 | 2017 | 2018 | |
4 | user_4 | | | |
如果有任何帮助,我将不胜感激
谢谢你@shrek在这里帮助我。我设法为透视值创建变量,但无法将变量放入透视中。因此,我得到了这方面的帮助,最终版本(针对11g)如下所示:
variable x REFCURSOR
DECLARE
exam_ids VARCHAR2(255);
BEGIN
SELECT
LISTAGG(''''
|| exam_id
|| ''' AS "'
|| exam_name
|| '"',',') WITHIN GROUP(
ORDER BY
exam_id ASC
)
INTO exam_ids
FROM
exam;
OPEN :x FOR 'SELECT
*
FROM
(
SELECT
u.user_id,
u.user_name,
e.exam_id,
eu.exam_date
FROM
users u
LEFT JOIN exam_user eu ON u.user_id = eu.user_id
LEFT JOIN exam e ON e.exam_id = eu.exam_id
ORDER BY
u.user_id
)
PIVOT ( MAX ( exam_date )
FOR exam_id
IN ( ' || EXAM_IDS || ' )
)
ORDER BY
1';
END;
/
print x
这在SQL开发人员和SQL*Plus中都可以使用。但在尝试将数据库与PHP文件一起使用时,情况并非如此。为此,我需要创建一个过程,然后可以从PHP文件中调用该过程。尝试使用PHP文件中的上述代码和解决方案时出现问题。这应该可以让您继续-
CREATE TABLE users
(user_id varchar2(9), user_name varchar2(11))
;
INSERT ALL
INTO users (user_id, user_name)
VALUES ('1', 'user_1')
INTO users (user_id, user_name)
VALUES ('2', 'user_2')
INTO users (user_id, user_name)
VALUES ('3', 'user_3')
INTO users (user_id, user_name)
VALUES ('4', 'user_4')
SELECT * FROM dual
;
CREATE TABLE exam
(exam_id varchar2(9), exam_name varchar2(11))
;
INSERT ALL
INTO exam (exam_id, exam_name)
VALUES ('1', 'exam_1')
INTO exam (exam_id, exam_name)
VALUES ('2', 'exam_2')
INTO exam (exam_id, exam_name)
VALUES ('3', 'exam_3')
SELECT * FROM dual
;
CREATE TABLE exam_user
(exam_id varchar2(9), user_id varchar2(9), exam_date varchar2(11))
;
INSERT ALL
INTO exam_user (exam_id, user_id, exam_date)
VALUES ('1', '1', '2017')
INTO exam_user (exam_id, user_id, exam_date)
VALUES ('1', '2', '2018')
INTO exam_user (exam_id, user_id, exam_date)
VALUES ('1', '3', '2017')
INTO exam_user (exam_id, user_id, exam_date)
VALUES ('2', '3', '2018')
SELECT * FROM dual
;
查询-
SELECT * FROM (
SELECT U.USER_ID, U.USER_NAME, E.EXAM_NAME,EU.EXAM_DATE
FROM USERS U, EXAM E, EXAM_USER EU
WHERE U.USER_ID = EU.USER_ID(+)
AND E.EXAM_ID(+) = EU.EXAM_ID
ORDER BY U.USER_ID
)
PIVOT (MAX(EXAM_DATE) FOR EXAM_NAME IN ('exam_1' as exam_1, 'exam_2' as exam_2,'exam_3' as exam_3))
order by 1
;
输出-
到目前为止,你尝试过什么?我尝试过将这3个结果放到一个表中,我想我可能可以从中拉出最后一个透视表,但我也没有做到。一个很好的答案。直到连接使用的逗号。您应该学会使用明确、正确、标准的
JOIN
语法。感谢您的反馈,我将继续尝试。