Oracle简单树查询
Oracle简单树查询--oracle针对树型结构的查询select lpad('-', level, '-') || ename from empstart with (ename = 'KING')connect by prior empno = mgr;查询结果基于emp表中数据以树形结构显示:LPAD('-',LEVEL,'-')||ENAME---------------------------------KING--JONES---SCOTT----ADAMS---FORD----SMITH--BLAKE---ALLEN---WARD---MARTIN---TURNER---JAMES--CLARK---MILLER