树数据集

-- leveal列最大值是多少，就写多少个join，如果想自动化，就需要存储循环或游标

select lev0.typeID typeID0,lev1.typeID typeID1,lev2.typeID typeID2,

       lev0.fullName fullName0,lev1.fullName fullName1,lev2.fullName fullName2

from (

select typeID,parID,fullName from tableName 

where 1=1

  and leveal=0

) lev0

left join (

select typeID,parID,fullName from tableName 

where 1=1

  and leveal=1

) lev1 on lev0.typeID=lev1.parID

left join (

select typeID,parID,fullName from tableName 

where 1=1

  and leveal=2

) lev2 on lev1.typeID=lev2.parID