Question

我想通过与之前的条目（针对该帐户）进行比较来检索表中的记录。请查看下面的表格和数据。

在我想要的输出中，

ID_NUM  DELIVERY_TYPE
100     2                
101     2
102     2

说明：我需要， 100因为它是第一次出现DELIVERY_TYPE IS 2（旧记录有1） 101因为它是第一次出现DELIVERY_TYPE IS 2（旧记录有3） 102因为此ID_NUM和DELIVERY_TYPE IS 2只有一个条目

我不需要 103因为最近的DELIVERY_TYPE是1，即使它有DELIVERY_TYPE IS 2 104因为它有两个或多个带有DELIVERY_TYPE IS 2的记录

任何团体都知道如何实现这个结果？

CREATE TABLE DEMO
  (
    ID_NUM         NUMBER(10,0),
    DELIVERY_TYPE  NUMBER(2,0),
    NAME           VARCHAR2(100),
    CREATED_DATE   DATE
  );


INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (100, 2, TO_DATE('10-FEB-12 11:08:49 AM', 'DD-MON-RR HH:MI:SS AM'));
INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (100, 1, TO_DATE('29-JAN-12 11:09:00 AM', 'DD-MON-RR HH:MI:SS AM'));

INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (101, 2, TO_DATE('09-FEB-12 11:09:26 AM', 'DD-MON-RR HH:MI:SS AM'));
INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (101, 3, TO_DATE('14-JAN-12 11:09:33 AM', 'DD-MON-RR HH:MI:SS AM'));

INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (102, 2, TO_DATE('02-FEB-12 10:09:26 AM', 'DD-MON-RR HH:MI:SS AM'));

INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (103, 1, TO_DATE('01-FEB-12 10:09:26 AM', 'DD-MON-RR HH:MI:SS AM'));
INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (103, 2, TO_DATE('02-JAN-12 11:09:33 AM', 'DD-MON-RR HH:MI:SS AM'));

INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (104, 2, TO_DATE('02-FEB-12 10:09:26 AM', 'DD-MON-RR HH:MI:SS AM'));
INSERT INTO DEMO
  (ID_NUM, DELIVERY_TYPE, CREATED_DATE)
VALUES
  (104, 2, TO_DATE('02-FEB-12 10:09:26 AM', 'DD-MON-RR HH:MI:SS AM'));

Answer 1

使用LAG功能。

如果你为你的例子发布一个小的值表而不是（/除了你的）insert语句，这可能会更容易。

Answer 2

虽然我不完全理解您的规则，但此查询将为您提供给定输入的所需输出：

  select ID_NUM, DELIVERY_TYPE
    from (  select ID_NUM, DELIVERY_TYPE, CREATED_DATE
              from DEMO
          group by ID_NUM, DELIVERY_TYPE, CREATED_DATE
            having count(*) = 1) CNT1
   where CREATED_DATE = (select max(CREATED_DATE)
                           from DEMO D
                          where D.ID_NUM = CNT1.ID_NUM)
         and DELIVERY_TYPE <> 1
order by ID_NUM, DELIVERY_TYPE, CREATED_DATE

如果你展开会发生什么，例如，ID_NUM只有一个条目，但它不是DELIVERY_TYPE = 1，那么也许我可以更新。

Answer 3

您可以使用ROW_NUMBER（）函数通过在ID_NUM上进行分区并按CREATED_DATE降序排序来隔离最近的行。然后确定多个DELIVERY_TYPE = 2的出现次数以过滤结果集：

SELECT ID_NUM, DELIVERY_TYPE
FROM (SELECT ID_NUM, DELIVERY_TYPE,
             ROW_NUMBER() OVER (PARTITION BY ID_NUM
                                ORDER BY CREATED_DATE DESC) AS RN
      FROM DEMO)
WHERE RN = 1
AND DELIVERY_TYPE = 2
MINUS
SELECT ID_NUM, DELIVERY_TYPE
FROM (SELECT ID_NUM, DELIVERY_TYPE, COUNT(*) AS REC_COUNT
      FROM DEMO
      WHERE DELIVERY_TYPE = 2
      GROUP BY ID_NUM, DELIVERY_TYPE
      HAVING COUNT(*) > 1)

这将返回预期的结果。

Answer 4

以下查询为每个id_num返回一条记录，其中最后一个delivery_type为2，而值2仅出现在delivery_type一次：

SELECT DISTINCT id_num, last_delivery_type
FROM   (SELECT id_num,
               FIRST_VALUE(delivery_type) 
                  OVER (PARTITION BY id_num 
                        ORDER BY created_date DESC) 
                  AS last_delivery_type,
               COUNT(CASE WHEN delivery_type = 2 
                          THEN 2 ELSE NULL END) 
                  OVER (PARTITION BY id_num) AS delivery_type_2_cnt
        FROM   demo)
WHERE  last_delivery_type = 2 AND delivery_type_2_cnt = 1

SQL：根据特定条件将行与上一行进行比较

4 个答案: