如果我没理解错的话

case when "n_dim_city_senderDim"."sendercityname" ='تهران'           then '1' 
     when "n_dim_city_senderDim"."PROVINCENAME"  IN ('البرز', 'تهران') then '2' 
end

返回1，而您期望它返回2。这是因为有些行同时包含province_name和sendercityname，它们都等于/，并且包含在您指定的值中。
如果provincename应该优先，则将条件切换为

case when "n_dim_city_senderDim"."PROVINCENAME"  IN ('البرز', 'تهران') then '1' 
     when "n_dim_city_senderDim"."sendercityname" ='تهران'           then '2' 
end

**[编辑]**说明：

样本数据：

SQL> select * from test order by 1;

SENDERCITYNAME  PROVINCENAME
--------------- ---------------
Montreal        Quebec
Winnipeg        Manitoba

第一个查询：

SQL> select
  2    sendercityname,
  3    provincename,
  4    case when sendercityname = 'Montreal'            then 1
  5         when provincename in ('Quebec', 'Manitoba') then 2
  6    end as result
  7  from test
  8  order by 1;

SENDERCITYNAME  PROVINCENAME        RESULT
--------------- --------------- ----------
Montreal        Quebec                   1
Winnipeg        Manitoba                 2

第二个查询，其CASE表达式与第一个查询相反：

SQL> select
  2    sendercityname,
  3    provincename,
  4    case when provincename in ('Quebec', 'Manitoba') then 1
  5         when sendercityname = 'Montreal'            then 2
  6    end as result
  7  from test
  8  order by 1;

SENDERCITYNAME  PROVINCENAME        RESULT
--------------- --------------- ----------
Montreal        Quebec                   1
Winnipeg        Manitoba                 1

SQL>

看到区别了吗？