group by 中的 case 语句

Question

Getting this error ORA-12704: character set mismatch

SELECT name,
 YEAR,
PERIOD,
ENTITY,
CASE WHEN VALUE = 'USD Total' then 'USD' ELSE VALUE end as VALUE,
sum(amount)
from stats1
group by
name,
 YEAR,
PERIOD,
ENTITY,
CASE WHEN VALUE = 'USD Total' then 'USD' ELSE VALUE end,
''''

Answer 1

The below code is working but why isnt it accepting the else part....i want to pass value as it is if value is other than 'USD Total'

SELECT name,
 YEAR,
PERIOD,
ENTITY,
CASE WHEN VALUE = 'USD Total' then 'USD' end as VALUE,
sum(amount)
from stats1
group by
name,
 YEAR,
PERIOD,
ENTITY,
CASE WHEN VALUE = 'USD Total' then 'USD' end

Answer 2

SELECT
        name                                                            ,
        YEAR                                                            ,
        PERIOD                                                          ,
        ENTITY                                                          ,
        CASE WHEN VALUE = 'USD Total' THEN 'USD' ELSE VALUE END AS VALUE,
        SUM(amount)
FROM
        stats1
GROUP BY
        name  ,
        YEAR  ,
        PERIOD,
        ENTITY,
        VALUE