带有参数名和值的group by的JPA命名查询

我不熟悉Hibernate,需要使用Group by在我的实体上编写一个JPA命名查询。

这就是我的实体看起来的样子:

@Entity
@NamedQueries({
@NamedQuery(name="Transaction.getByYear",
        query="from Transaction where year=:year"),
@NamedQuery(name="Transaction.ByTimestamp",
        query="from Transaction where year=:year order by Timestamp desc"),
@NamedQuery(name="Transaction.ByActiveStatusAndTimestamp",
query="from Transaction where year=:year and itemStatus=:itemStatus order by Timestamp desc"),
@NamedQuery(name="Transaction.sumByYear",
        query="SELECT SUM(amount) from Transaction where year=:year")
})
public class Transaction {
@Id
@GeneratedValue
@Column(unique = true)
private int itemId;

@Column
private String itemName;

@Column
private int amount;

@Column
@Enumerated(EnumType.STRING)
private Category itemCategory;
}

这是我的类别枚举:

public enum Category {


ONBOARDING("Onboarding"),


EDUCATION("Education"),


EQUIPMENT("Equipment"),


SOFTWARE("Software");

private final String category;

    Category(final String category){
    this.category = category;
}

@Override
public String toString() {
    return category;
}

}

我需要一个查询来计算这些类别中每一个花费的金额之和。

@NamedQuery(name="Transaction.sumByFood", query="SELECT SUM(amount) from Transaction group by Category.FOOD") 

(我想这就是我们直接在命名查询中给出枚举的方式。如果我错了,请纠正我)

有什么方法可以编写一个命名查询,允许我通过以下方式将参数名称和值发送到组:

@NamedQuery(name="Transaction.sumByFood", query="SELECT SUM(amount) from Transaction group by itemCategory=:itemCategory")

然后通过类别,我想得到总和? 请帮我做这个。