HQL-COUNT（IF（））在编译时给出QuerySyntaxException

Question

我试图获取状态等于ACCEPTED的AdmissionForms的数量，但此查询未能这样做。

在存储库中，

SELECT COUNT(IF(status='ACCEPTED',1,NULL)), COUNT(IF(status='PENDING',1,NULL)) FROM  admissionforms;

我遇到的异常，

org.hibernate.hql.internal.ast.QuerySyntaxException: expecting CLOSE, found '(' near line 1, column 16 [SELECT COUNT(if(status = 'ACCEPTED',1,NULL)) FROM admissionforms]

Answer 1

为什么不只包含WHERE子句呢？

SELECT COUNT(*) AS ACCEPTED 
FROM admissionforms
WHERE status = 'ACCEPTED';

但是，条件聚合也可以这样做：

SELECT SUM(CASE WHEN status = 'ACCEPTED' THEN 1 ELSE 0 END) AS ACCEPTED
FROM admissionforms;