我有一个这样的语句,我需要将多个别名组合成另一个和,然后得到一个输出。
select
t1.id,
sum(t2.answ = t1.answ) as answerA,
sum(t3.answ = t1.answ) as answerM,
sum(t4.answ = t1.answ) as answerD,
sum(answerA + answerM + answerD) as total
from t1
left join t2 on t2.id = t1.t2fk
left join t3 on t3.id = t1.t3fk
left join t4 on t4.id = t1.t4fk
group by t1.id // updated
sum(answerA + answerM + answerD) as total
