Oracle 21c

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create table your_table (column_1) as
select '1223B' from dual union all
select '123C' from dual union all
select '028409d' from dual union all
select 'abce' from dual union all
select 'ABCf' from dual union all
select 'xya1' from dual union all
select 'abc-' from dual union all
select null from dual
8 rows affected

select column_1,
  case when substr(column_1, -1) = lower(substr(column_1, -1)) then 1 else 0 end as flag
from your_table


COLUMN_1
FLAG


1223B
0

123C
0

028409d
1

abce
1

ABCf
1

xya1
1

abc-
1

null
0


select column_1,
  case when substr(column_1, -1) != upper(substr(column_1, -1)) then 1 else 0 end as flag
from your_table


COLUMN_1
FLAG


1223B
0

123C
0

028409d
1

abce
1

ABCf
1

xya1
0

abc-
0

null
0