如果顺序，Oracle sql查询将两组日期分组

Question

我有下一张桌子：

EMPLOYEE	CODE	START_DATE	END_DATE
02097368	F7H3	09/07/2018	20/10/2018
02097368	F7H3	21/10/2018	05/01/2019
02097368	F7H3	06/01/2019	12/01/2019
02097368	F7H3	13/01/2019	02/02/2019
02097368	F7H3	03/02/2019	13/04/2019
02097368	F7S3	14/04/2019	04/01/2020
02097368	F7S3	05/01/2020	24/03/2020
02097368	F7S3	31/01/2021

我想按员工、代码和顺序日期对数据进行分组（end_date 到下一个 start_date，如果它晚 1 天）

期望的结果：

EMPLOYEE	CODE	START_DATE	END_DATE
02097368	F7H3	09/07/2018	13/04/2019
02097368	F7S3	14/04/2019	24/03/2020
02097368	F7S3	31/01/2021

我正在尝试这个，但我没有得到想要的结果

SELECT EMPLOYEE,
       CODE,
       MIN (START_DATE) AS START_DATE,
       MAX (END_DATE)
          KEEP (DENSE_RANK FIRST ORDER BY END_DATE DESC NULLS FIRST)
          AS END_DATE
  FROM (SELECT T.*,
               ROW_NUMBER ()
                  OVER (PARTITION BY EMPLOYEE ORDER BY START_DATE)
                  AS seqnum_i,
               ROW_NUMBER ()
               OVER (PARTITION BY EMPLOYEE, CODE ORDER BY START_DATE)
                  AS seqnum_ir
          FROM CODE_HIST T
         WHERE EMPLOYEE= '02097368') T
GROUP BY ID_EMPLEADO, (seqnum_i - seqnum_ir), CODE;

实际结果：

EMPLOYEE	CODE	START_DATE	END_DATE
02097368	F7H3	09/07/2018	13/04/2019
02097368	F7S3	14/04/2019

Answer 1

尽管我知道这不是最优雅的查询，但我通过以下查询解决了这个问题。请将 TABLE_1 替换为保存数据的实际表名或视图

运行以下命令时，我检索到以下结果

SELECT EMPLOYEE, CODE, MIN(START_DATE), MAX(END_DATE) FROM 
(
     SELECT EMPLOYEE, CODE, START_DATE, END_DATE, CASE
     WHEN (TEMP1=1 OR TEMP2=1) THEN 'ONE_CLASS'
     ELSE 'OTHER' END  CLASS_X
     FROM            
                (SELECT EMPLOYEE, CODE, 
                START_DATE, END_DATE,
                X AS TEMP1, LEAD(X) OVER (ORDER BY START_DATE) AS TEMP2
                            FROM (
                            SELECT EMPLOYEE, CODE,  
                            LAG(END_DATE) OVER (ORDER BY START_DATE) AS PREV_PERIOD_END_DATE, 
                            START_DATE, END_DATE,
                            START_DATE - LAG(END_DATE) OVER (ORDER BY START_DATE) AS X
                            FROM TABLE_2
                            ORDER BY START_DATE) A
                            ) B
                            ) C
GROUP BY EMPLOYEE, CODE, CLASS_X
ORDER BY MIN(START_DATE)

结果：

导致我不知道如何格式化为表格的文本形式：

员工代码最小值（START_DATE）最大值（END_DATE） 02097368 F7H3 09-JUL-18 13-APR-19 02097368 F7S3 14-APR-19 24-MAR-20 02097368 F7S3 31-JAN-21 -