如何在SQL中设置临时列的条件？

Question

USE COLEGIUU
SELECT NmStud, PrenStud, 
      NotaMedie = (SELECT AVG(N.Nota) FROM [Notele] N WHERE N.idStudent = S.IdStudent)
  FROM Student S
  WHERE idStudent IN(SELECT idStudent FROM Notele GROUP BY idStudent)

NotaMedie是具有可计算值的临时列。我如何仅输出NotaMedie> 9的行？

Answer 1

您可以使用having子句加入，聚合和过滤：

select s.NmStud, s.PrenStud, avg(n.Nota) NotaMedie
from student s
inner join notele n on n.idStudent = s.idStudent
group by s.NmStud, s.PrenStud
having avg(n.Nota) > 9