Java HQL如何对实体中的列表使用sum函数

大家好，我需要你们的帮助

如何将HQL的Sum函数用于一个实体的列表

我试图通过代码示例来解释我的问题

这是我的发票

@Entity
public class Invoice extends ExtendedBaseEntity {

@Column(nullable = true,length = 50)
private String invoiceNo;

@Column(nullable = true)
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX", timezone = "EET")
private Date invoiceDate;

@Column(nullable = true,precision = 10,scale = 2)
private BigDecimal amount; getters and setters.....

这是我的文件实体。这个实体有一个发票列表

@Entity    
public class File extends ExtendedBaseEntity {
@Column(nullable = true, length = 50)
private String name;

@Column(nullable = true, length = 50)
private String surname;

@Column(nullable = true, length = 50)
private String lawyerCode;

@Column(nullable = true, length = 50)
private String sellerCode;

@OneToMany(cascade = CascadeType.REMOVE, fetch = FetchType.EAGER)
@Fetch(FetchMode.SELECT)
@JoinColumn(name = "MBSFILE_OID")
private List<Invoice> invoices = new ArrayList<Invoice>(); setters and getters ....

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我该如何应对？你能帮我吗？

好的，你需要一份

groupby

声明好的，非常感谢我处理了。好的，你需要一份

groupby

声明好的，非常感谢我处理了。

SELECT DISTINCT
            SUM(invoice.amount) AS totalAmount
FROM file 
LEFT JOIN file.invoices AS invoice