exists 的问题

今天同事发以下两个sql来问我,怎么运行结果一样

Select Id
*y8Nk#fMiaU0      From Tb_Admin_RoleITPUB个人空间l8V"y1Wj'i
      Where Exists (Select Id From Tb_Admin_Role Connect By Prior Id = Parent_Id Start With Id = 222);ITPUB个人空间-^G[E,HDyf^
           
8l|Rr]|0Select IdITPUB个人空间s;hm,W?Gm.P}
      From Tb_Admin_Role
_ U(@)hp/e1kl:Ci`0      Where Exists (Select Id From Tb_Admin_Role Connect By Prior Id = Parent_Id Start With Id = 1);

一看,写法有问题

这样写才是对的,两表之间ID必须关联

Select IdITPUB个人空间p,I5c^!dx\
      From Tb_Admin_Role a
2A`$],O.K0      Where Exists (Select Id From Tb_Admin_Role b  where a.id=b.id   Connect By Prior Id = Parent_Id Start With Id = 222);ITPUB个人空间+z5esd;jw!DN
           

XNb$}y0Select Id
_ [)T!vTx"g8A:RcX5B0      From Tb_Admin_Role aITPUB个人空间hV$cUQz"F
      Where Exists (Select Id From Tb_Admin_Role  b where a.id=b.id Connect By Prior Id = Parent_Id Start With Id = 1);

其实上面这个

Select IdITPUB个人空间M/T%\?F8M
      From Tb_Admin_Role a

i(f["]0l2`;r E c+D'q"H3I0      Where Exists (Select Id From Tb_Admin_Role b  where a.id=b.id   Connect By Prior Id = Parent_Id Start With Id = 222);
S!v3x%ez2EO0           

就等价于

Select Id From Tb_Admin_Role  Connect By Prior Id = Parent_Id Start With Id = 222

前面是画蛇添足了,呵呵