Oracle中order by case 用法

select *
        from ly_familyinformation
       where  iszfbtperson = ‘0‘
       and file_id=‘105047013002523‘
       order by case
                  when relation = ‘购房人/申请人‘ then
                   0
                  when relation = ‘配偶‘ then
                   1
                  else
                   2
                end,
                applyer;