CREATE TABLE plch_employees
(
   employee_id   INTEGER
, last_name     VARCHAR2 (100)
, salary        NUMBER
)
/

BEGIN
   INSERT INTO plch_employees
        VALUES (100, 'Smith', 100000);
   COMMIT;
END;
/

然后我运行如下的代码：
DECLARE
   CURSOR emps_cur
   IS
        SELECT * FROM plch_employees
      ORDER BY employee_id;

   emp_rec   emps_cur%ROWTYPE;
BEGIN
   INSERT INTO plch_employees
        VALUES (200, 'Jones', 1000000);

OPEN emps_cur;

ROLLBACK;

   LOOP
      FETCH emps_cur INTO emp_rec;
      EXIT WHEN emps_cur%NOTFOUND;

DBMS_OUTPUT.put_line (emp_rec.last_name);
END LOOP;

CLOSE emps_cur;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.put_line ('Error');
END;
/

你将无法再从游标FETCH数据，ORACLE会抛出异常：
ORA-01002: fetch out of sequence

如果你的游标带有FOR UPDATE子句，在打开游标之后你做了提交，那么再试图FETCH时同样会发生这个错误。

ITPub博客

fetch out of sequence