0

我在帽子下面的存储过程工作正常。无论是谁，我都希望能够检查是否存在带有 YesterdayDate 的数据集，如果不存在，请将YesterdayDate替换为TodayDate。

如果此计数为 0，我正在尝试诸如检查之类select count(1) from TableName where DATASET_DATE = YesterdayDate的方法，但是假设有任何方法，我找不到一种方法来将此检查添加到代码中，而无需修改或破坏其他所有内容。

存储过程：

CREATE OR REPLACE function DO_STUFF
(TodayDate date, YesterdayDate date)

return integer is status integer;

BEGIN 

DECLARE
  CURSOR c_stuff
  IS
    SELECT 
        <several_fields>
    FROM 
        TableName TODAY 
        LEFT JOIN TableName YESTERDAY
        ON  TODAY.KEY1 = YESTERDAY.KEY1
        WHERE TODAY.DATASET_DATE = TodayDate
        AND YESTERDAY.DATASET_DATE = YesterdayDate
    ORDER BY 
        TODAY.KEY1 ASC;
BEGIN
  FOR r_lines IN c_stuff
  LOOP
    <do_some_stuff>
  END LOOP;
END;

COMMIT;

STATUS := 0;

return status;

END
/

有谁知道如何实现这一点？

-- 编辑澄清：我确实需要使用这两个谓词。在 <do_some_stuff> 部分中，我主要进行计算并比较两个数据集（今天与昨天）并使用结果更新一些字段。我想在这里完成的是通过将今天与今天进行比较并避免结果数据不正确来处理昨天进程没有运行并且没有昨天数据集的情况。

4

2 回答 2

1

我不确定您要使用该功能做什么。无论我从您的第一行问题中了解到什么，您都可以尝试以下代码 -

CREATE OR REPLACE function DO_STUFF(TodayDate     date,
                                    YesterdayDate date)
RETURN INTEGER
IS
new_date DATE;
CNT NUMBER;
BEGIN
     SELECT COUNT(*)
       INTO CNT
       FROM TableName TODAY 
       LEFT JOIN TableName YESTERDAY ON TODAY.KEY1 = YESTERDAY.KEY1
      WHERE TODAY.DATASET_DATE = TodayDate
        AND YESTERDAY.DATASET_DATE = YesterdayDate
      ORDER BY TODAY.KEY1 ASC;
     IF CNT = 0 THEN
        RETURN TodayDate;
     ELSE
        RETURN YesterdayDate;
     END IF;
EXCEPTION
         WHEN OTHERS THEN
              RETURN '1900-01-01';
END;
于 2021-08-23T21:08:25.873 回答
0

你可以做到这一切没有JOIN：

CREATE OR REPLACE function DO_STUFF(
  TodayDate date,
  YesterdayDate date
) return integer
IS
  CURSOR c_stuff IS
    SELECT key1,
           field1,
           field2,
           field3
    FROM   (
      SELECT key1,
             field1,
             field2,
             field3,
             DENSE_RANK() OVER (
               ORDER BY CASE dataset_date WHEN YesterdayDate THEN 1 ELSE 2 END
             ) AS rnk
      FROM   TableName 
      WHERE  DATASET_DATE IN ( TodayDate, YesterdayDate )
    )
    WHERE rnk = 1
    ORDER BY KEY1 ASC;
BEGIN 
  FOR r_lines IN c_stuff
  LOOP
    <do_some_stuff>
  END LOOP;

  return 0;
END
/
于 2021-08-23T21:15:07.853 回答