Question

我有这个实体：

批次，麦芽，国家/地区-批次包含麦芽（@ManyToMany），麦芽来自某个国家/地区（@ManyToOne）。关系如下：

批次：

@JoinTable(name="batch_malt",
    joinColumns = @JoinColumn(name="batch_id"),
    inverseJoinColumns = @JoinColumn(name="malt_id"))
private Set<Malt> malts = new HashSet<>();

麦芽：

@NotNull
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="country_id")
private Country country;

@ManyToMany(mappedBy="malts")
private Set<Batch> batches;

国家/地区：没有映射，因为它是Malt的@ManyToOne。

国家服务：

@Override
    public void deleteById(Long countryIdToDelete) {

        Set<Malt> malts = maltRepository.findByCountry_id(countryIdToDelete);
        if (malts != null) {
            for (Malt tempMalt : malts) {
                log.debug("Deleting country from malt number: " + tempMalt.getMaltName());
                tempMalt.setCountry(null);
            }
            maltRepository.deleteById(countryIdToDelete);
        }
    }

我想删除国家（我不想删除麦芽-应该改为null）

当我尝试删除国家/地区时得到

There was an unexpected error (type=Internal Server Error, status=500).
could not execute statement; SQL [n/a]; constraint ["FKM636T1NDS3GNKJC6WG8MCG21L: PUBLIC.BATCH_MALT FOREIGN KEY(MALT_ID) REFERENCES PUBLIC.MALT(ID) (2)"; SQL statement: delete from malt where id=? [23503-197]]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement
org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint ["FKM636T1NDS3GNKJC6WG8MCG21L: PUBLIC.BATCH_MALT FOREIGN KEY(MALT_ID) REFERENCES PUBLIC.MALT(ID) (2)"; SQL statement:
delete from malt where id=? [23503-197]]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

Caused by: org.h2.jdbc.JdbcSQLException: Naruszenie więzów integralności: "FKM636T1NDS3GNKJC6WG8MCG21L: PUBLIC.BATCH_MALT FOREIGN KEY(MALT_ID) REFERENCES PUBLIC.MALT(ID) (2)"
Referential integrity constraint violation: "FKM636T1NDS3GNKJC6WG8MCG21L: PUBLIC.BATCH_MALT FOREIGN KEY(MALT_ID) REFERENCES PUBLIC.MALT(ID) (2)"; SQL statement:
delete from malt where id=? [23503-197]

我应该更改什么才能删除国家/地区？

链接到整个仓库：https://github.com/fangirsan/maruszka-new

如何删除与另一个实体相关的实体

0 个答案: