ORA-00904 (Sybase migrate to ORACLE)

Hi Experts,

Recently, I used SQL Developper to convert a sybase into Oracle, however, the following problem is encountered:
SYBASE code:

update #temp_result
 set chinese_name =  ltrim(rtrim(chinese_name)) + big5
 from ccc_code
 where code = cccode6

Oracle translate above into the following:

 MERGE INTO tt_temp_result
   USING (SELECT tt_temp_result.ROWID row_id, LTRIM(RTRIM(chinese_name)) || big5 AS chinese_name
   FROM ccc_code
   WHERE code = cccode6) src
   ON ( tt_temp_result.ROWID = src.row_id )
   WHEN MATCHED THEN UPDATE SET chinese_name = src.chinese_name;

but it raised ORA-00904 error,

tt_temp_result is a global temporary table: