Solution to distinct multi-column problem combined with group

Table table1
Id RegName PostionSN PersonSN
1 Shandong Qilu pharmaceutical 223 2
2 Shandong Qilu pharmaceutical 224 2
3 Beijing Urban Construction Company 225 2
4 technology companies 225 2

The result I want to obtain is

Id RegName PostionSN PersonSN
1 Shandong Qilu pharmaceutical 223 2
3 Beijing Urban Construction Company 225 2
4 technology companies 225 2

Select distinct RegName, PostionSN, PersonSN from table1

If multiple columns of distinct are queried, do not use the same

Only group

Use group by RegName
Select * from table1 where id in (select min (id) from table1 group by RegName) and PersonSN = 2