对多个列取消PIVOT和union的SQL查询

我正在努力实现以下结果

投入，表A

-----+--------+--------+-----+-------+----------+----------+---------+
sub  |   c_f  |  type  | F_G | layer | dec_2020 | jan_2021 | feb_2021
-----+--------+--------+-----+-------+----------+----------+---------+
A600 |  Core  | Analog |  F  |  50   |  d_val_1 | j_val_1  | f_val_1
A600 |  Core  | Analog |  F  |  60   |  d_val_2 | j_val_2  | f_val_2
A600 |  future| Analog |  G  |  32   |  d_val_3 | j_val_3  | f_val_3
-----+--------+--------+-----+-------+----------+----------+---------+

我将获得这个输出

-----------+-----+--------+--------+-----+-------+----------+
month_year | sub |   c_f  |  type  | F_G | layer | values   
-----------+-----+--------+--------+-----+-------+----------+
dec_2020   |A600 |  Core  | Analog |  F  |  50   |  d_val_1 
dec_2020   |A600 |  Core  | Analog |  F  |  60   |  d_val_2 
dec_2020   |A600 |  future| Analog |  G  |  32   |  d_val_3 
jan_2021   |A600 |  Core  | Analog |  F  |  50   |  j_val_1  
jan_2021   |A600 |  Core  | Analog |  F  |  60   |  j_val_2    
jan_2021   |A600 |  future| Analog |  G  |  32   |  j_val_3   
feb_2021   |A600 |  Core  | Analog |  F  |  50   |  f_val_1  
feb_2021   |A600 |  Core  | Analog |  F  |  60   |  f_val_2
feb_2021   |A600 |  future| Analog |  G  |  32   |  f_val_3
-----+--------+--------+-----+-------+----------+----------+

我正在尝试使用交叉应用，我可以创建“月\年”列，但我不知道如何合并上一列中的值。 谢谢你的帮助

我认为这基本上是适用的：

使用UNPIVOT：

select v.month_year, a.sub, a.c_f, a.type, a.F_G, a.layer, v.value
from a cross apply
     (values ('dec_2020', a.dec_2020),
             ('jan_2021', a.jan_2021),
             ('feb_2021', a.feb_2021)
     ) v(month_year, value);
         
          

SELECT month_year, sub,  [c_f],  [type], [F_G], layer, [val] 
FROM   
   (SELECT *  
   FROM t) p  
UNPIVOT  
   (val  FOR month_year IN   
      ([dec_2020], [jan_2021], [feb_2021])  
)AS unpvt;