如何计算别名列上的聚合函数SUM?
SELECT a.question_id,
a.level,
Count(a.question_id) AS rank,
Sum(rank) AS total
FROM logs AS a,
question AS b
WHERE a.question_id = b.q_id
AND a.level = '2'
GROUP BY a.question_id
ORDER BY rank DESC
最佳答案
只需使用(SELECT别名)包装您的重用别名:
SELECT a.question_id,
a.level,
COUNT(a.question_id) AS rank,
SUM(SELECT(rank)) AS total
FROM logs AS a,
question AS b
WHERE a.question_id = b.q_id
AND a.level = '2'
GROUP BY a.question_id
ORDER BY rank DESC