如何结合这两个查询

Question

我对这两个查询使用相同的表和列，但我有不同的别名和avg函数。我将如何能够将这两个查询与UNION ALL结合起来，因为我想要从它们中选择每一行。当我有不同的select语句时，显然我不能这样做。我怎么能结合这两个查询？

SELECT GRADE_TYPE_CODE, ROUND(TO_CHAR(NUMERIC_GRADE),2) AS GRADE 
FROM GRADE 
WHERE STUDENT_ID = 10 AND SECTION_ID = 5 
ORDER BY GRADE_TYPE_CODE DESC,NUMERIC_GRADE DESC; 



SELECT 'Average is:' AS GRADE_TYPE_CODE,AVG(GRADE) AS GRADE 
FROM 
(
    SELECT AVG(NUMERIC_GRADE) AS GRADE 
FROM GRADE 
WHERE STUDENT_ID = 10 AND SECTION_ID = 5 
GROUP BY GRADE_TYPE_CODE 
) myInnerTable; 

Answer 1

不知道这里是什么问题。为什么不在两个查询之间放置“union all”，并将ORDER BY子句移到最后？

SELECT GRADE_TYPE_CODE, ROUND(TO_CHAR(NUMERIC_GRADE),2) AS GRADE 
FROM GRADE 
WHERE STUDENT_ID = 10 AND SECTION_ID = 5 

union all 

SELECT 'Average is:' AS GRADE_TYPE_CODE,AVG(GRADE) AS GRADE 
FROM 
(
    SELECT AVG(NUMERIC_GRADE) AS GRADE 
FROM GRADE 
WHERE STUDENT_ID = 10 AND SECTION_ID = 5 
GROUP BY GRADE_TYPE_CODE 
) myInnerTable 

order by 1 desc, 2 desc 

http://sqlfiddle.com/#!4/99a16/19/0

Answer 2

我想你可以create a temporary table然后UNION ALL从两个单独的查询。