Java Hibernate条件平均值：BigDecimal而不是Double

Question

休眠条件是将Projections.avg（“ column”）映射到Double 。

如何强制Hibernate将该函数映射到BigDecimal ？

Hibernate是hibernate-core-4.1.9.Final.jar

Answer 1

应该可以将AvgProjection子类重写为getTypes以返回BigDecimal并改用此投影。

即

public class AvgBDProjection extends AvgProjection{

    public AvgBDProjection(String propertyName) {
        super(propertyName);
    }

    public Type[] getTypes(Criteria criteria, CriteriaQuery criteriaQuery)
    throws HibernateException {
        return new Type[] { org.hibernate.type.BigDecimalType.INSTANCE };
   }
}