不知道你的两段查询结果是怎么个结构,可以考虑使用 json_object 对查询结果进行转换
```
SELECT json_object('uid' VALUE UID,
'age' VALUE age,
'name' VALUE NAME,
'birthday' VALUE birthday)
FROM user_table
UNION
SELECT json_object('uid' VALUE sys_guid(),
'age' VALUE 11,
'name' VALUE 'aaa',
'birthday' VALUE SYSDATE - 11)
FROM dual
UNION
SELECT json_object('uid' VALUE sys_guid(),
'age' VALUE 22,
'name' VALUE 'bbb',
'birthday' VALUE SYSDATE - 22)
FROM dual
```
相关资料:
https://docs.oracle.com/en/database/oracle/oracle-database/12.2/sqlrf/JSON_OBJECT.html#GUID-1EF347AE-7FDA-4B41-AFE0-DD5A49E8B370