通过附加数字将重复值转换为非重复值

你可以用 row_number() . 以下假定排序规则不区分大小写(默认)

select t.col1, t.col2,
       (case when count(*) over (partition by col1, col2, col3) = 1
             then col1
             else col3 + convert(varchar(255), row_number() over (partition by col1, col2, col3 order by col1) )
        end) as new_col3
from t;

您可以轻松地将其转换为更新:

with toupdate as (
      select t.*,
             (case when count(*) over (partition by col1, col2, col3) = 1
                   then col1
                   else col3 + convert(varchar(255), row_number() over (partition by col1, col2, col3 order by col1) )
              end) as new_col3
      from t
     )
update toupdate
    set col3 = new_col3
    where new_col3 <> col3;

您可以使用 COLLATE ,如果不是默认值。