pivot 行变列

with temp as(
select '四川省' nation ,'成都市' city,'第一' ranking from dual union all
select '四川省' nation ,'绵阳市' city,'第二' ranking from dual union all
select '四川省' nation ,'德阳市' city,'第三' ranking from dual union all
select '四川省' nation ,'宜宾市' city,'第四' ranking from dual union all
select '湖北省' nation ,'武汉市' city,'第一' ranking from dual union all
select '湖北省' nation ,'宜昌市' city,'第二' ranking from dual union all
select '湖北省' nation ,'襄阳市' city,'第三' ranking from dual
)
select * from （select nation,city,ranking from temp）pivot (max(city) for
ranking in ('第一' as 第一,'第二' as 第二,'第三' as 第三,'第四' as 第四));