oracle 外联接
oracle 外联接 “(+)” 的用法：
Connected to Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 Connected as scottSQL> select deptno from dept; DEPTNO------ 10 20 30 40 50 SQL> select ename from emp; ENAME----------SMITHALLENWARDJONESMARTINBLAKECLARKSCOTTKINGTURNERADAMSJAMESFORDMILLER 14 rows selected SQL> select d.deptno,e.ename from dept d,emp e where e.deptno(+)=d.deptno; DEPTNO ENAME------ ---------- 20 SMITH 30 ALLEN 30 WARD 20 JONES 30 MARTIN 30 BLAKE 10 CLARK 20 SCOTT 10 KING 30 TURNER 20 ADAMS 30 JAMES 20 FORD 10 MILLER 50 40 16 rows selected SQL> select d.deptno,e.ename from dept d,emp e where e.deptno=d.deptno(+); DEPTNO ENAME------ ---------- 20 SMITH 30 ALLEN 30 WARD 20 JONES 30 MARTIN 30 BLAKE 10 CLARK 20 SCOTT 10 KING 30 TURNER 20 ADAMS 30 JAMES 20 FORD 10 MILLER 14 rows selected
?结果表示 “(+)” 出现在哪张表旁边，则那张表为补充表。
