Oracle SQL 在重复值开始之前查找最大数量

Question

我正在尝试使用查询在重复值开始之前查找列中的最大值。我有三列 - 年、工作编号、小时费率

在某一年（可能会有所不同）之后，费率开始重复。

使用下面的数据，我需要找到每个职位编号的最高费率年份。

期望的结果集：

年份	职位编号	每小时费率
1998	6454	48.07765385469215
1996	1126	45.662133671135376
2000	9196	42.02154384293608

创建表“my_GRID1_TEST” (“年份”数字(38,0), “职位代码”编号(38,0), “HOURLY_RATE”号(38,15) )

Year    Jobnumber  hourly_rate
2024    1126    35.582755
2023    1126    35.96506525
2022    1126    36.3511986025
2021    1126    36.74119328852501
2020    1126    37.13508792141026
1999    1126    44.59125280927884
1998    1126    44.94554923034844
1997    1126    45.30250287457605
1996    1126    45.662133671135376
1995    1126    45.662133671135376
1994    1126    45.662133671135376
2024    9196    33.05523
2023    9196    33.05523
2022    9196    33.412265
2021    9196    33.77287035
2005    9196    39.11636105858664
2004    9196    39.42959579152604
2003    9196    39.745179784962485
2002    9196    40.0631306583497
2001    9196    40.38346616328733
2000    9196    42.02154384293608
1999    9196    42.02154384293608
1998    9196    42.02154384293608
1997    9196    42.02154384293608
2024    6454    37.494306250000005
2023    6454    37.8957320125
1999    6454    46.95322894974278
1998    6454    48.07765385469215
1997    6454    48.07765385469215
1996    6454    48.07765385469215
1995    6454    48.07765385469215
1994    6454    48.07765385469215
1993    6454    48.07765385469215

Answer 1

您可以使用

LEAD

和

ROW_NUMBER

分析函数：

SELECT year, jobnumber, hourly_rate
FROM   (
  SELECT year, jobnumber, hourly_rate,
         ROW_NUMBER() OVER (PARTITION BY jobnumber ORDER BY hourly_rate DESC) AS rn
  FROM   (
    SELECT year, jobnumber, hourly_rate,
           CASE
           WHEN LEAD(hourly_rate) OVER (PARTITION BY jobnumber ORDER BY year DESC)
                != hourly_rate
           THEN 1
           ELSE 0
           END AS has_changed
    FROM   table_name
  )
  WHERE  has_changed = 1
)
WHERE  rn = 1;

对于样本数据：

CREATE TABLE table_name (Year, Jobnumber, hourly_rate) AS
SELECT 2024, 1126, 35.582755 FROM DUAL UNION ALL
SELECT 2023, 1126, 35.96506525 FROM DUAL UNION ALL
SELECT 2022, 1126, 36.3511986025 FROM DUAL UNION ALL
SELECT 2021, 1126, 36.74119328852501 FROM DUAL UNION ALL
SELECT 2020, 1126, 37.13508792141026 FROM DUAL UNION ALL
SELECT 1999, 1126, 44.59125280927884 FROM DUAL UNION ALL
SELECT 1998, 1126, 44.94554923034844 FROM DUAL UNION ALL
SELECT 1997, 1126, 45.30250287457605 FROM DUAL UNION ALL
SELECT 1996, 1126, 45.662133671135376 FROM DUAL UNION ALL
SELECT 1995, 1126, 45.662133671135376 FROM DUAL UNION ALL
SELECT 1994, 1126, 45.662133671135376 FROM DUAL UNION ALL
SELECT 2024, 9196, 33.05523 FROM DUAL UNION ALL
SELECT 2023, 9196, 33.05523 FROM DUAL UNION ALL
SELECT 2022, 9196, 33.412265 FROM DUAL UNION ALL
SELECT 2021, 9196, 33.77287035 FROM DUAL UNION ALL
SELECT 2005, 9196, 39.11636105858664 FROM DUAL UNION ALL
SELECT 2004, 9196, 39.42959579152604 FROM DUAL UNION ALL
SELECT 2003, 9196, 39.745179784962485 FROM DUAL UNION ALL
SELECT 2002, 9196, 40.0631306583497 FROM DUAL UNION ALL
SELECT 2001, 9196, 40.38346616328733 FROM DUAL UNION ALL
SELECT 2000, 9196, 42.02154384293608 FROM DUAL UNION ALL
SELECT 1999, 9196, 42.02154384293608 FROM DUAL UNION ALL
SELECT 1998, 9196, 42.02154384293608 FROM DUAL UNION ALL
SELECT 1997, 9196, 42.02154384293608 FROM DUAL UNION ALL
SELECT 2024, 6454, 37.494306250000005 FROM DUAL UNION ALL
SELECT 2023, 6454, 37.8957320125 FROM DUAL UNION ALL
SELECT 1999, 6454, 46.95322894974278 FROM DUAL UNION ALL
SELECT 1998, 6454, 48.07765385469215 FROM DUAL UNION ALL
SELECT 1997, 6454, 48.07765385469215 FROM DUAL UNION ALL
SELECT 1996, 6454, 48.07765385469215 FROM DUAL UNION ALL
SELECT 1995, 6454, 48.07765385469215 FROM DUAL UNION ALL
SELECT 1994, 6454, 48.07765385469215 FROM DUAL UNION ALL
SELECT 1993, 6454, 48.07765385469215 FROM DUAL;

输出：

年份	职位编号	HOURLY_RATE
1997	1126	45.30250287457605
1999	6454	46.95322894974278
2001	9196	40.38346616328733

小提琴