从每个组的Oracle获取最大值

奥马里·维克多·奥莫萨（Omari Victor Omosa）

我想根据ID_DATE以下记录中的列获取每个组中的最高值。通过...分组ID_TOPIC

CREATE TABLE DA_TBL(
    DATA_ID  VARCHAR2(50),
    REF_DESC VARCHAR2(50),
    DATE_L DATE NOT NULL,
    ID_TOPIC  VARCHAR2(50),
    ID_DATE NUMBER
);

INSERT all 
INTO DA_TBL  VALUES  ('1','sample 1',CURRENT_TIMESTAMP, 'local', 1)
INTO DA_TBL  VALUES  ('2','sample 2',CURRENT_TIMESTAMP, 'tradition', 2)
INTO DA_TBL  VALUES  ('3','sample 2',CURRENT_TIMESTAMP, 'gospel', 3)
INTO DA_TBL  VALUES  ('4','sample 4',CURRENT_TIMESTAMP, 'local', 4)
INTO DA_TBL  VALUES  ('5','sample 5',CURRENT_TIMESTAMP, 'gospel', 5)
INTO DA_TBL  VALUES  ('6','sample 6',CURRENT_TIMESTAMP, 'tradition', 6)
INTO DA_TBL  VALUES  ('7','sample 7',CURRENT_TIMESTAMP, 'gospel', 7)
INTO DA_TBL  VALUES  ('8','sample 8',CURRENT_TIMESTAMP, 'local', 8)
INTO DA_TBL  VALUES  ('9','sample 9',CURRENT_TIMESTAMP, 'tradition', 9)
INTO DA_TBL  VALUES  ('10','sample 10',CURRENT_TIMESTAMP, 'local', 10)
INTO DA_TBL  VALUES  ('11','sample 11',CURRENT_TIMESTAMP, 'gospel', 11)
SELECT * FROM dual;

我想要的是：

DATA_ID|REF_DESC |ID_TOPIC |ROWNUMBER|
-------|---------|---------|---------|
9      |sample 9 |tradition|        1|
10     |sample 10|local    |        1|
11     |sample 11|gospel   |        1|

我得到的是：

DATA_ID|REF_DESC|ID_TOPIC |ROWNUMBER|
-------|--------|---------|---------|
9      |sample 9|tradition|        1|
8      |sample 8|local    |        1|
7      |sample 7|gospel   |        1|

我尝试过的

 SELECT *
  FROM (SELECT DATA_ID, REF_DESC, ID_TOPIC 
              , ROW_NUMBER() OVER (PARTITION BY ID_TOPIC ORDER BY DATA_ID DESC) AS rownumber
         FROM  DA_TBL ORDER BY DATA_ID DESC)
 WHERE rownumber = 1;

苍蝇

尝试以下查询：

SELECT 
  t1.DATA_ID,
  t1.REF_DESC,
  t1.ID_TOPIC
FROM yourTable t1
JOIN (
  SELECT 
    ID_TOPIC, 
    MAX(ID_DATE) AS maxIdDate
  FROM yourTable 
  GROUP BY ID_TOPIC
) t2 ON t1.ID_TOPIC = t2.ID_TOPIC AND t1.ID_DATE = t2.maxIdDate

我认为您在查询中使用了错误的列，因此如果以这种方式修复它，它也应该起作用：

SELECT 
  *
FROM (
  SELECT 
    DATA_ID, 
    REF_DESC, 
    ID_TOPIC,
    ROW_NUMBER() OVER (PARTITION BY ID_TOPIC ORDER BY ID_DATE DESC) AS rownumber
  FROM DA_TBL
) t
WHERE rownumber = 1;

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