您可以使用ROW_NUMBER（）和LEAD（）分析函数：

WITH
    tbl AS
        (   Select 'A' "USR", To_Date('01.05.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual Union All
            Select 'A' "USR", To_Date('13.07.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual Union All
            Select 'B' "USR", To_Date('01.04.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual Union All
            Select 'B' "USR", To_Date('25.08.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual Union All
            Select 'C' "USR", To_Date('15.05.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual Union All
            Select 'C' "USR", To_Date('15.07.2023', 'dd.mm.yyyy') "SDATE", To_Date('01.01.2099', 'dd.mm.yyyy') "EDATE" From Dual 
        )
Select      USR, SDATE, EDATE, 
          Case  When ROW_NUMBER() OVER(Partition By USR Order By SDATE) = 1
                Then Lead(SDATE) OVER(Partition By USR Order By SDATE)
          Else  EDATE
          End "NEW_EDATE"
From        tbl 
--  R e s u l t :
--  USR SDATE     EDATE     NEW_EDATE
--  --- --------- --------- ---------
--  A   01-MAY-23 01-JAN-99 13-JUL-23
--  A   13-JUL-23 01-JAN-99 01-JAN-99
--  B   01-APR-23 01-JAN-99 25-AUG-23
--  B   25-AUG-23 01-JAN-99 01-JAN-99
--  C   15-MAY-23 01-JAN-99 15-JUL-23
--  C   15-JUL-23 01-JAN-99 01-JAN-99

可以合并此结果以更新您的数据：

Merge Into tbl t
Using   (   Select  USR, SDATE, EDATE, 
                    Case    When ROW_NUMBER() OVER(Partition By USR Order By SDATE) = 1
                            Then Lead(SDATE) OVER(Partition By USR Order By SDATE)
                    Else  EDATE
                    End "NEW_EDATE"
            From        tbl 
        ) x ON(x.USR = t.USR And x.SDATE = t.SDATE And x.EDATE = t.EDATE)
When MATCHED 
Then UPDATE SET t.EDATE = x.NEW_EDATE
Where t.EDATE != x.NEW_EDATE