PLSQL中对cursor的where current of 的使用例子

开始

DECLARE

  CURSOR emp_cursor IS

    SELECT empno, ename, dname

    FROM emp_cpy, dept

    WHERE  emp_cpy.deptno=dept.deptno

    AND  emp_cpy.deptno = 20

    FOR UPDATE OF sal NOWAIT;



  emp_record emp_cursor%ROWTYPE;



BEGIN

   

LOOP



  IF NOT emp_cursor%ISOPEN  THEN

     OPEN emp_cursor;

  END IF; 

  

  FETCH emp_cursor INTO  emp_record; 

  EXIT WHEN emp_cursor%NOTFOUND;

  

  UPDATE emp_cpy 

  SET empno=1000 WHERE CURRENT OF emp_cursor;

  

  dbms_output.put_line

     ('empno is:' || emp_record.empno || '-- emp name is:' || emp_record.ename ||'-- dept is:' || emp_record.dname);

     

END LOOP;



IF emp_cursor%ISOPEN  THEN

     dbms_output.put_line('Now to close cursor!');

     CLOSE emp_cursor;

END IF; 



END;

当时看到结果：

anonymous block completed

empno is:7369-- emp name is:SMITH-- dept is:RESEARCH

empno is:7566-- emp name is:JONES-- dept is:RESEARCH

empno is:7788-- emp name is:SCOTT-- dept is:RESEARCH

empno is:7876-- emp name is:ADAMS-- dept is:RESEARCH

empno is:7902-- emp name is:FORD-- dept is:RESEARCH

Now to close cursor!

我们再查询看看：

SQL> select * from emp_cpy where deptno=20;



     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM

---------- ---------- --------- ---------- --------- ---------- ----------

    DEPTNO

----------

      1000 SMITH      CLERK           7902 17-DEC-80        800

        20



      1000 JONES      MANAGER         7839 02-APR-81       2975

        20



      1000 SCOTT      ANALYST         7566 19-APR-87       3000

        20





     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM

---------- ---------- --------- ---------- --------- ---------- ----------

    DEPTNO

----------

      1000 ADAMS      CLERK           7788 23-MAY-87       1100

        20



      1000 FORD       ANALYST         7566 03-DEC-81       3000

        20





SQL> 

再前面的整个的代码结束的时候，自动进行了提交：在结果集的范畴里，改变了 deptno的值。

 结束