如何从列表中删除一个实体并添加一个新实体而不违反唯一约束?

@Entity
public class Calculation {
    @Id
    @GeneratedValue(strategy = IDENTITY)
    private Long id;

    @OneToMany(fetch = LAZY, cascade = ALL, orphanRemoval = true)
    @JoinColumn(name = "calculation_id", referencedColumnName = "id", nullable = false, foreignKey = @ForeignKey(name = "fk_standard_part"))
    private List<Part> parts;
}

@Entity
public class Part {
    @Column
    private String position;

    @Column
    private String positionDetail;
}

我正在使用Hibernate和Spring数据:

1. 我从数据库中提取计算结果,然后填充零件列表。
3. 我用position='SIDE',position\u detail='WINDOW'创建新零件,并将其添加到列表中。
4. 我使用crudepository.save()保存计算

请告知我做错了什么。如果可能,我不想更新零件实体。它有许多其他属性可能需要清除,因此我更喜欢替换它。非常感谢。

编辑1: 代码如下:

public Part repairStandardPart(Long calcId, String partNumber) {
    Part part = fetchNewPart(partNumber);
    Calculation calculation = getCalculation(calcId);
    // If there's a part with the same position allready I want to remove it...
    deletePartsAtPosition(calculation.getParts(), part.getPosition(), part.getSidePosition());
    // ...and then add the new one.
    calculation.getParts().add(part);
    calculationRepository.save(calculation);
    return part;
}

private void deletePartsAtPosition(List<Part> parts, String position, String positionDetail) {
    parts.removeIf(p -> Objects.equals(p.getPosition(), position) && Objects.equals(p.getPositionDetail(), positionDetail));
}