SQL> SELECT a.ename,b.ename FROM emp a,emp b 2 WHERE a.mgr=b.empno;ENAME ENAME ---------- ---------- SMITH FORD ALLEN BLAKE WARD BLAKE JONES KING MARTIN BLAKE BLAKE KING CLARK KING SCOTT JONES TURNER BLAKE ADAMS SCOTT JAMES BLAKE FORD JONES MILLER CLARK13 rows selectedSQL>
SELECT a.ename,b.ename FROM emp a,emp b WHERE a.mgr=b.empno;
嗯,写得不错…… 但是,没有显示KING的记录。
SQL> SELECT a.ename,b.ename mgrname FROM emp a,emp b 2 WHERE a.mgr=b.empno(+);ENAME MGRNAME ---------- ---------- SMITH FORD ALLEN BLAKE WARD BLAKE JONES KING MARTIN BLAKE BLAKE KING CLARK KING SCOTT JONES KING TURNER BLAKE ADAMS SCOTT JAMES BLAKE FORD JONES MILLER CLARK14 rows selectedSQL>
2 WHERE a.mgr=b.empno;ENAME ENAME
---------- ----------
SMITH FORD
ALLEN BLAKE
WARD BLAKE
JONES KING
MARTIN BLAKE
BLAKE KING
CLARK KING
SCOTT JONES
TURNER BLAKE
ADAMS SCOTT
JAMES BLAKE
FORD JONES
MILLER CLARK13 rows selectedSQL>
FROM emp a,emp b
WHERE a.mgr=b.empno;
嗯,写得不错……
但是,没有显示KING的记录。
2 WHERE a.mgr=b.empno(+);ENAME MGRNAME
---------- ----------
SMITH FORD
ALLEN BLAKE
WARD BLAKE
JONES KING
MARTIN BLAKE
BLAKE KING
CLARK KING
SCOTT JONES
KING
TURNER BLAKE
ADAMS SCOTT
JAMES BLAKE
FORD JONES
MILLER CLARK14 rows selectedSQL>