您正在查找SQL标准的IS NOT DISTINCT FROM运算符，不幸的是，Oracle中没有实现该运算符。然而，它可以用DECODE()来模拟。
例如，您可以执行以下操作：

with Desired_Column_Combination as (
  Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
  Select 'A1' ColA,'B1' ColB,'' ColC from dual union all --Should've 3 records
  Select 'A2' ColA,'' ColB,'C3' ColC from dual union all --Should've 2 records
  Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
)
select * 
from SampleTable S
where exists (
  select 1
  from Desired_Column_Combination d
  where decode(s.ColA, d.ColA, 1, 0) = 1
    and decode(s.ColB, d.ColB, 1, 0) = 1
    and decode(s.ColC, d.ColC, 1, 0) = 1
);

字符串
测试结果：

COLA  COLB  COLC  DESIRED_COLD  DESIRED_COLE  DESIRED_COLF 
 ----- ----- ----- ------------- ------------- ------------ 
 A1    B1    null  28            24            23           
 A1    B1    null  13            90            36           
 A1    B1    null  27            27            82           
 A1    B2    C2    54            58            34           
 A2    null  C3    22            27            12           
 A2    null  C3    14            78            50           
 A3    B1    C1    44            70            53           
 A3    B1    C1    38            13            11

型
参见db<>fiddle上的运行示例。

你需要记住“NULL不等于任何东西-甚至不等于它本身”。
从Fiddle中借用和调整代码：

With Desired_Column_Combination as (
-- Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
Select 'A1' ColA,'B1' ColB, null ColC from dual -- union all --Should've 3 records
-- Select 'A2' ColA,'' ColB,'C3' ColC from dual -- union all --Should've 2 records
-- Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
  )
Select * from SampleTable S
where (ColA,ColB,ColC) 
  in (Select ColA,ColB,ColC from Desired_Column_Combination)
union all
Select * from SampleTable S
where (ColA,ColB) 
  in (Select ColA,ColB from Desired_Column_Combination)
 and ColC is null
union all
Select * from SampleTable S
where (ColA,ColC) 
  in (Select ColA,ColC from Desired_Column_Combination)
 and ColB is null

字符串
returns three rows的数据。

With Desired_Column_Combination as (
-- Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
-- Select 'A1' ColA,'B1' ColB, null ColC from dual -- union all --Should've 3 records
Select 'A2' ColA,'' ColB,'C3' ColC from dual -- union all --Should've 2 records
-- Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
  )
Select * from SampleTable S
where (ColA,ColB,ColC) 
  in (Select ColA,ColB,ColC from Desired_Column_Combination)
union all
Select * from SampleTable S
where (ColA,ColB) 
  in (Select ColA,ColB from Desired_Column_Combination)
 and ColC is null
union all
Select * from SampleTable S
where (ColA,ColC) 
  in (Select ColA,ColC from Desired_Column_Combination)
 and ColB is null

型
returns two rows。
因此，您需要在Desired_Column_Combination的选择中适当地满足NULL值。
如果需要调整/进一步详细说明，请予以说明。