select * from TEST0531 

1、将女生爱好合并为一行

select '女',(hobby) hobby from TEST0531 where sex= '女'

wm_concat(列名),该函数可以把列值以","号分隔起来,并显示成一行

2、将爱好拆分显示（注意：数据库中字段内数据应以英文逗号隔开：value1,value,value3）

select distinct (name), regexp_substr(hobby, '[^,]+', 1, level) hobby
  from TEST0531
connect by regexp_substr(hobby, '[^,]+', 1, level) is not null 

注意：distinct (name):使查询数据根据name唯一，这样查询出的数据不会重复

注意：regexp_substr(hobby, '[^,]+', 1, level：运用了正则表达式（具体意思没搞明白），
且这句话应与 connect by regexp_substr(hobby, '[^,]+', 1, level) is not null一同出现。

3、获取与周有相同爱好的人

select distinct (name)
  from (select distinct (name),
                        regexp_substr(hobby, '[^,]+', 1, level) hobby
          from TEST0531
        connect by regexp_substr(hobby, '[^,]+', 1, level) is not null) h
where instr( (select hobby from TEST0531 where name ='周'),h.hobby)>0

instr('abc','a');表示在abc中查找有没有a这个字符。>0表示字符存在

4、获取与周有相同爱好的人的所有信息

select *
  from TEST0531
 where name in
       (select distinct (name)
          from (select distinct (name),
                                regexp_substr(hobby, '[^,]+', 1, level) hobby
                  from TEST0531
                connect by regexp_substr(hobby, '[^,]+', 1, level) is not null) h
         where instr((select hobby from TEST0531 where name = '周'), h.hobby) > 0)