??????????????QQС????????????????????????????????????????????????????????????????????????????????????????????? pid??Σ???????Ч????????и?FullPath??Ρ?(?Щ??????????????Σ????????????????к?????)??FullPath??ο????? id-id-id….?????????????洢???????????????? like ?????в??????????????
?????????????????????洢????????????????????????????????????????????????????д洢?????????????????￡??洢??Ч????????????????????Щ????????д??????????????
???????????????????

?????????????????????????left ??right??????Σ??????????????????????????????????????????left??????????right=left+1??????????????right?????????????????
??????????????????????????? fruit ??? ??????? where left between 2 and 11
??????????????full path ?????? banana??????? where left<8 and right >9
??????????????????????red yellow??????????????update left =left+2 where left>=7 ??update right=right+2 where right>7????? ?????left rigt????? 7??8?? ???????????
???????????????id????int?????????????????????Ч???????fullPath??ε????????????????????????like??Ч?????
??????????У???????????????????????????????pid?????children???????????鷳Щ?????????2?????
??????left between x and y order by left ?????
??????????????????left=?????Left+1?????????????????????????????????????????????????????????????????????
????OK?????μ?????????????