将重复值更改为一个

Question

我有一张桌子：

id location_id company_id
1            1          1
2            2          1
3            3          1
4            4          5
5            5          5
6            6          5

问题是如何将所有值location_id更改为一个公司中的最低值，如下所示：

id location_id company_id
1            1          1
2            1          1
3            1          1
4            4          5
5            4          5
6            4          5

编辑：McNets代码工作，但我有另一个问题，这是我编辑的代码：

update t1
set location_id = t2.min_loc
from opinion t1 
join (select company_id, min(location_id) min_loc
      from opinion
      group by company_id) t2
on t2.company_id = t1.company_id
join (select id, house_number, street, city
      from location) t3
on t3.id = t1.location_id
where t3.house_number is null and (t3.street is null or t3.street = '') and t3.city is null

哪个适用于SQL Server 2016，但我的数据库是MariaDB，我收到错误

Syntax error near 'from opinion t1 join (select company_id, min(location_id) min_loc from op' at line 3

有什么建议？

Answer 1

create table tbl (id int, location_id int, company_id int)
insert into tbl values
(1, 1, 1),
(2, 2, 1),
(3, 3, 1),
(4, 4, 5),
(5, 5, 5),
(6, 6, 5);
GO

6 rows affected

update tbl t1
join (select company_id, min(location_id) min_loc
      from   tbl
      group by company_id) t2
on t2.company_id = t1.company_id
set location_id = t2.min_loc;

✓

select * from tbl;

id | location_id | company_id
-: | ----------: | ---------:
 1 |           1 |          1
 2 |           1 |          1
 3 |           1 |          1
 4 |           4 |          5
 5 |           4 |          5
 6 |           4 |          5

dbfiddle here