如何将日期时间值从行转换为列

您可以使用row_number()和聚合：

select 
    shift,
    max(case when rn = 1 then starttime end) starttime1,
    max(case when rn = 2 then starttime end) starttime2,
    max(case when rn = 3 then starttime end) starttime3
from (
    select t.*, row_number() over(partition by shift order by starttime) rn
    from mytable t
) t
group by shift