一组值的 Oracle SQL 过程 MAX、MIN、AVG答案

【问题标题】：Oracle SQL procedure MAX, MIN, AVG of set of values一组值的 Oracle SQL 过程 MAX、MIN、AVG
【发布时间】：2017-06-15 12:32:15
【问题描述】：

我已经创建了这个程序：

SET SERVEROUTPUT ON;
CREATE OR REPLACE PROCEDURE sales_period (
   purchdate1 IN DATE,
   purchdate2 IN DATE
)
IS 
    CURSOR purchcur IS
    SELECT purchases.purchdate, max(purchases.purchprice) max1, 
           min(purchases.purchprice) min1, avg(purchases.purchprice) avg1
    FROM purchases
    WHERE purchases.purchdate BETWEEN sales_period.purchdate1 AND 
          sales_period.purchdate2
    group by purchases.purchdate;
    purchrow purchcur%ROWTYPE;
    e_foreign_key_error EXCEPTION;
    PRAGMA EXCEPTION_INIT (e_foreign_key_error, -2291);
BEGIN
 OPEN purchcur;
  LOOP
   FETCH purchcur INTO purchrow;
    DBMS_OUTPUT.PUT_LINE('Sales report: ');
    DBMS_OUTPUT.PUT_LINE('Date sold: ' || purchrow.purchdate);
    DBMS_OUTPUT.PUT_LINE('Max saleprice: ' || purchrow.max1);
    DBMS_OUTPUT.PUT_LINE('Avg saleprice: ' || purchrow.avg1);
    DBMS_OUTPUT.PUT_LINE('Min saleprice: ' || purchrow.min1);
   EXIT WHEN purchcur%NOTFOUND;
  END LOOP;
EXCEPTION
  WHEN e_foreign_key_error THEN
      DBMS_OUTPUT.PUT_LINE('no existing field in parent table');
  CLOSE purchcur;
 END;
/

我要做的是输入两个日期，然后打印出销售报告，即该期间（输入的两个日期之间）的最高、平均和最低价格。所以，问题是我所做的是这样做的：

SQL> exec sales_period('1-Jun-15', '30-Aug-15');
Sales report:
Date sold: 03-JUL-15
Max saleprice: 1600
Avg saleprice: 1600
Min saleprice: 1600
Sales report:
Date sold: 05-JUL-15
Max saleprice: 5000
Avg saleprice: 5000
Min saleprice: 5000
Sales report:
Date sold: 10-AUG-15
Max saleprice: 3000
Avg saleprice: 3000
Min saleprice: 3000
Sales report:
Date sold: 02-JUN-15
Max saleprice: 2000
Avg saleprice: 2000
Min saleprice: 2000
Sales report:
Date sold: 07-JUL-15
Max saleprice: 1500
Avg saleprice: 1500
Min saleprice: 1500

我想要它做的是获取这些日期之间的所有价格，并计算出最大值、最小值和平均值并只显示一次。就像，让我们说......

01-Jul-2015 售价 1000

02-Jul-2015 售价为 1300

28-Jul-2015 售价 1500

我愿意exec sales_period('1-Jul-15', '30-Jul-15');

我希望它像这样打印出来：

Max: 1500, min: 1000, avg: 1300

不像我运行它时所做的那样 - 它在每个日期都执行它，并且没有得到最小值、最大值和平均值总体。我希望它得到整体的最小值、最大值和平均值。

我希望得到一些帮助！ - 谢谢！！

【问题讨论】：

标签： sql oracle stored-procedures max min

【解决方案1】：

您不想按 purchase_date 分组，因为您的范围内有多个日期，因此您有多个结果。

我也有点不确定你定义的异常。

在我看来，以下内容更符合您的要求；

CREATE OR REPLACE PROCEDURE sales_period (
   purchdate1 IN DATE,
   purchdate2 IN DATE
)
IS 
    l_max_price    NUMBER;
    l_min_price    NUMBER;
    l_avg_price    NUMBER

BEGIN

   SELECT max(purchases.purchprice) max1, 
          min(purchases.purchprice) min1,
          avg(purchases.purchprice) avg1
   INTO   l_max_price,
          l_min_price,
          l_avg_price        
    FROM purchases
    WHERE purchases.purchdate BETWEEN purchdate1 AND purchdate2;

   DBMS_OUTPUT.PUT_LINE('Sales report: ');
   DBMS_OUTPUT.PUT_LINE('Date range sold: ' || TO_CHAR(purchdate1,'DD-MON-YYYY')|| ' TO ' || TO_CHAR(purchdate2,'DD-MON-YYYY'));
   DBMS_OUTPUT.PUT_LINE('Max saleprice: ' || l_max_price);
   DBMS_OUTPUT.PUT_LINE('Avg saleprice: ' || l_avg_price);
   DBMS_OUTPUT.PUT_LINE('Min saleprice: ' || l_min_price);

EXCEPTION
  WHEN no_data_found THEN
      DBMS_OUTPUT.PUT_LINE('no data for the date range');
END;
/

请注意，我实际上并没有运行/编译它，所以它可能有奇怪的语法问题，但原则是不变的。

【讨论】：