Oracle Db 按两列分组

Question

我想按 2 列分组，我的第一个 table 是：

用户

ID Name Surname
1  joe   New
2  Ala   Bla
3  Cat   Kra
4  Zoo   Fles
5  Kat   Glo

工作：

ID BOSSID1 BOSSID2
1  1       2
2  2       3
3  2       1
4  2       5
5  3       5

而且我想看到 table "Work" 中的所有 Boss。

例如：

1 joe   New
2 Ala   Bla
3 Cat   Kra
5 Kat   Glo

Answer 1

试试这个：

select id, concat(name, ' ', surname) from
(
    select id, name, surname from users 
    where id in 
    (
      select distinct bossid1 from work

    ) OR id in 
    (
      select distinct bossid2 from work
    )
)

Answer 2

试试这个：

SELECT DISTINCT u.* FROM USERS u INNER JOIN WORK w 
ON (u.id = w.bossid1 OR u.id = w.bossid2)

Answer 3

你可以 union 然后加入 users table

SELECT CONCAT_WS(' ', U.Name, U.Surname)
FROM Users U
JOIN
(SELECT BOSSID1 as BossID
FROM WORK
UNION
SELECT BOSSID2 as BossID
FROM WORK
) T
on U.ID = T.BossID

Oracle Db 按两列分组

Oracle Db Group By Two Columns

mysql

sql

database

oracle