在SQL-oracle中的游标内使用游标

我在网上查找，看看是否可以找到一个示例，说明如何使用游标（在游标中）从两个表中获得所需的结果，但没有成功。所以我想知道是否有人可以给我举一些例子或者帮助我编写代码

数据：来自2个表

DEPARTMENT_ID DEPARTMENT_NAME    
------------- --------------------
           10 ACCOUNTING           
           50 EXECUTIVE            
           40 IT                   
           60 MARKETING            
           20 RESEARCH             
           30 SALES                

选择6行

EMPLOYEE_ID EMPLOYEE_NAME            SALARY DEPARTMENT_ID    MAX_SAL   MAX75SAL
----------- -------------------- ---------- ------------- ---------- ----------
       8000 BREWSTER                   2500                     2500       1875 
       7603 CLARK                      4000            50       5000       3750 
       7900 FISHER                     3000            30       3000       2250 
       7921 JACKSON                    2500            30       3000       2250 
       7566 JONES                      3000            10       3000       2250 
       7596 JOST                       4500            50       5000       3750 
       7839 KING                       5000            50       5000       3750 
       7944 LEE                        2400            20       3000       2250 
       7788 SCOTT                      2500            40       2900       2175 
       7910 SMITH                      2900            40       2900       2175 
       7886 STEEL                      2500            10       3000       2250 
       7610 WILSON                     3000            20       3000       2250 
       7999 WOLFE                      2500            20       3000       2250

起初，我得到了这样的结果：

ACCOUNTING              3000            2250      JONES
ACCOUNTING              3000            2250      STEEL
EXECUTIVE               5000            3750      CLARK
EXECUTIVE               5000            3750       JOST
EXECUTIVE               5000            3750       KING
IT                      2900            2175      SCOTT
IT                      2900            2175      SMITH
RESEARCH                3000            2250        LEE
RESEARCH                3000            2250     WILSON
RESEARCH                3000            2250      WOLFE
SALES                   3000            2250     FISHER
SALES                   3000            2250    JACKSON
N/A                     2500            1875   BREWSTER

但我需要它们像这样出现：

ACCOUNTING              3000            2250      JONES STEEL
EXECUTIVE               5000            3750      CLARK JOST KING
IT                      2900            2175      SCOTT SMITH
RESEARCH                3000            2250        LEE WILSON WOLFE
SALES                   3000            2250     FISHER JACKSON

其中，每个部门名称将只产生一行，但在末尾包含符合标准的员工姓名

我的代码：

DECLARE
-- First cursor 
CURSOR c_get_dept IS
        SELECT      department_id, department_name 
    FROM            department
ORDER BY        department_name;

-- Second cursor 
CURSOR c_get_emp (p_dept_id NUMBER) IS

select  z.employee_id, z.employee_name, z.salary, z.department_id,
max_sal,(z.max_sal *.75)  max75sal
from
(
SELECT employee_id, employee_name,salary,department_id, 
max(salary) over (partition by department_id) as max_sal
FROM        employee
ORDER BY employee_name
) z
WHERE salary > (max_sal*.75 )
order by z.employee_name;

v_flag NUMBER;
BEGIN
-- Open first cursor
FOR idx_1 IN c_get_dept LOOP
        v_flag := 0;
-- Open second cursor `
        FOR idx_2 IN c_get_emp(idx_1.department_id) LOOP
            IF v_flag = 0 THEN

DBMS_OUTPUT.PUT_LINE(idx_1.department_name || '   ' || idx_2.max_sal ||
                '   ' || idx_2.max75sal || '   ' || idx_2.EMPLOYEE_NAME);
                v_flag := 0;
            END IF;
        END LOOP;
IF v_flag = 0 THEN
        DBMS_OUTPUT.PUT_LINE('  No output.');
    END IF;

 END LOOP;
 END;

---

谢谢大家!

如果您使用的是Oracle 11.2，则可以使用listag函数（）来帮助您完成所要做的事情。以下查询生成您要查找的结果：

SELECT d.DEPARTMENT_NAME,
       MAX(e.SALARY) AS MAX_SALARY,
       MAX(e.SALARY)*0.75 AS MAX75,
       LISTAGG(e.EMPLOYEE_NAME, ' ')
         WITHIN GROUP (ORDER BY d.DEPARTMENT_NAME) AS EMPLOYEES
  FROM DEPARTMENT d
  INNER JOIN EMPLOYEE e
    ON e.DEPARTMENT_ID = d.DEPARTMENT_ID
  GROUP BY d.DEPARTMENT_NAME
  ORDER BY d.DEPARTMENT_NAME

如果目标是在PL/SQL块中使用多个游标，我建议尝试以下简单方法（注意并警告：未测试代码如下）：

分享和享受。

删除了我的“答案”，因为其他人认为这不是答案，而是澄清问题。总而言之：您正处于一个残酷的时期，试图让它与游标一起工作。并不是说这是不可能的，但是重新构造数据和使用双层功能要好得多。

DECLARE
  nDepartment_max_salary  NUMBER;
  strEmployees            VARCHAR2(32767);
BEGIN
  FOR dept IN (SELECT *
                 FROM DEPARTMENT
                 ORDER BY DEPARTMENT_NAME)
  LOOP
    nDepartment_max_salary := 0;
    strEmployees := NULL;

    FOR emp IN (SELECT *
                  FROM EMPLOYEE e
                  WHERE e.DEPARTMENT_ID = dept.DEPARTMENT_ID)
    LOOP
      nDepartment_max_salary := GREATER(nDepartment_max_salary, emp.SALARY);
      strEmployees := strEmployees || emp.EMPLOYEE_NAME || ' ';
    END LOOP; -- emp

    DBMS_OUTPUT.PUT_LINE(dept.DEPARTMENT_NAME || '   ' ||
                         nDepartment_max_salary || '   ' ||
                         nDepartment_max_salaray * 0.75 || '   ' ||
                         strEmployees);
  END LOOP;  -- dept
END;