MySQL 8.0

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create table test (id int primary key, pos int unique);
insert into test values (1,1),(2,3),(3,2),(4,4);
select * from test;

Records: 4  Duplicates: 0  Warnings: 0

id
pos

1
1

3
2

2
3

4
4

insert into test values
(3,3), (2,2)
on duplicate key update pos = values(pos);

Duplicate entry '3' for key 'test.pos'

select * from test;

id
pos

1
1

3
2

2
3

4
4

insert into test values
(2,0), (3,3), (2,2)
on duplicate key update pos = values(pos);

Records: 3  Duplicates: 3  Warnings: 1

select * from test;

id
pos

1
1

2
2

3
3

4
4