Question

您好我正在尝试使用for循环来检索oracle pl / sql中的数据但是我收到错误可以有人帮助我

SET SERVEROUTPUT ON
DECLARE

  fname employees.first_name%TYPE;
  empid employees.employee_id%TYPE;
  CURSOR emp_cursor IS
  SELECT employee_id,first_name from employees ORDER BY employee_id;

BEGIN

  open emp_cursor;  
  FOR empid IN emp_cursor loop

  DBMS_OUTPUT.PUT_LINE('employee id is ' ||empid || 'first name is '||fname);

end LOOP;

END;

我在DBMS输出行上遇到错误，例如变量的数量或类型不正确。我正在尝试从oracle示例模式中的employees表中检索员工ID和名字。

有人可以指导我吗

Answer 1

在CURSORS中使用FOR..LOOP。

SET SERVEROUTPUT ON
DECLARE
  /* DECLARE Cursor */
  CURSOR emp_cursor IS
  SELECT employee_id,first_name from employees ORDER BY employee_id;

BEGIN
  FOR empid IN emp_cursor loop
     /* empid already has the row details, you don't need to have any other variables */
     DBMS_OUTPUT.PUT_LINE('employee id is ' ||empid.employee_id || 'first name is '||empid.first_name);

  end LOOP;

END;
/

使用OPEN FETCH和CLOSE

SET SERVEROUTPUT ON
DECLARE

  fname employees.first_name%TYPE;
  empid employees.employee_id%TYPE;
  CURSOR emp_cursor IS
  SELECT employee_id,first_name from employees ORDER BY employee_id;

BEGIN

  open emp_cursor; 

  /* LOOP until the cursor is empty */
  LOOP 
      FETCH emp_cursor INTO empid,fname;
      /* Now we fetch data from cursor, and put it into our variables */
      EXIT WHEN emp_cursor%NOTFOUND;

      DBMS_OUTPUT.PUT_LINE('employee id is ' ||empid || 'first name is '||fname);
  END LOOP;

  /* As we OPEN'ed the cursor manually, we have to CLOSE it without fail */
  CLOSE emp_cursor;

END;
/

Oracle PL / SQL使用带有for循环的游标进行数据检索

1 个答案: