CASE WHEN LIKE 查询 SQL

Question

你能告诉我这个查询有什么问题吗？

SELECT Students.Class
FROM Students
GROUP BY Students.class
HAVING SUM(CASE WHEN Name LIKE '*a' THEN 1 ELSE 0 END) > COUNT(*)/2;    

我必须检查名字是否以字母“a”结尾，然后比较每个班级中这些名字的数量是否高于这些班级所有学生的一半。

Answer 1

MS Access 不支持case。

SELECT Students.Class
FROM Students
GROUP BY Students.class
HAVING SUM(IIF(Name LIKE '*a', 1, 0)) > COUNT(*)/2; 

Answer 2

我假设你必须只显示类：

Select Class
From Students
Where Name Like '*a'
Group by Class
Having SUM(*) > (Select COUNT(*)/2 
                From Students)