-- 检查WATERSHED_SERVICE表的结构
SELECT column_name, data_type, data_length, char_length, collation_name
FROM user_tab_columns
WHERE table_name = 'WATERSHED_SERVICE';

-- 检查数据库的字符集设置
SELECT parameter, value
FROM nls_database_parameters
WHERE parameter IN ('NLS_CHARACTERSET', 'NLS_NCHAR_CHARACTERSET');