col ename format a15
col job format a15
select lpad(' ', 3 * (level = 1)) || ename ename,
lpad(' ', 3 * (level = 1)) || job job
from emp
where job <> 'CLERK'
start with mgr is null
connect by mgr = prior empno;
执行时提示"缺少又括号",搞不明白
col job format a15
select lpad(' ', 3 * (level = 1)) || ename ename,
lpad(' ', 3 * (level = 1)) || job job
from emp
where job <> 'CLERK'
start with mgr is null
connect by mgr = prior empno;
执行时提示"缺少又括号",搞不明白
what's meaning
但level的具体作用有没有人能详细说明一下
level是start with connect by 这个递归树里的一个隐含量，表示在树中的级别，也就是第几级的对象。