oracle对查询到的数据进行求和统计

对查询结果中的列中的数据进行统计求和，求和结果作为新的一行添加到查询结果的末尾，

SELECT 
  CASE WHEN text IS NOT NULL THEN text ELSE'合计'END text,
  CASE WHEN text IS NOT NULL THEN id ELSE 0 END id,
  SUM(total_num)AS total_num
FROM (SELECT text,
       (CASE 
         WHEN ID = 1 THEN 1
         WHEN ID = 2 THEN 2
         WHEN ID = 3 THEN 4
         WHEN ID = 4 THEN 4
         WHEN ID = 5 THEN 5
         WHEN ID = 6 THEN 4
         WHEN ID = 7 THEN 4
        END) id,
        SUM(total_num) total_num
      FROM (
           SELECT aa.id, aa.text, 1 total_num  
           FROM (
                SELECT 1 id,'AAA' text FROM dual
                UNION
                SELECT 2 id,'BBB' text FROM dual
                UNION
                SELECT 3 id,'CCC' text FROM dual
                UNION
                SELECT 4 id,'CCC' text FROM dual
                UNION
                SELECT 6 id,'CCC' text FROM dual
                UNION
                SELECT 7 id,'CCC' text FROM dual
                UNION
                SELECT 5 id,'DDD' text FROM dual
                )aa 
           )
            GROUP BY text,(CASE 
                            WHEN id = 1 THEN 1
                            WHEN id = 2 THEN 2
                            WHEN id = 3 THEN 4
                            WHEN id = 4 THEN 4
                            WHEN id = 5 THEN 5
                            WHEN id = 6 THEN 4
                            WHEN id = 7 THEN 4
                           END )     
            ORDER BY id
) A
GROUP BY rollup(text,id)  
HAVING text IS NULL OR id IS NOT NULL

查询结果中就这样多了一个统计行：