OneToMany关系不能在春天用liquibase保存

Question

我正试图在spring中构建一个数据模型，该模型通过一对多关系级联到3个级别，但我无法让它与liquibase脚本一起使用。

我使用的是带有Kotlin的spring-boot和带有PostgreSQL数据库的liquibase。

到目前为止我做了什么：

• 减少代码，只包含不起作用的部分(见下文(
• 我用@JoinTable和@JoinColumn尝试了@OneToMany，我也用@ManyToMany尝试了同样的方法，以排除@OneToMany的问题
• 我在没有liquibase的情况下运行了相同的代码(如下(，让Hibernate/JPA从模型中创建表
• 这确实有效，所以我从这些表中生成了liquibase脚本，但它们看起来和我自己的完全一样(除了密钥名(
• 使用这些模型检索数据是可行的(如果我直接通过SQL插入数据(

老实说，我不确定问题是在模型、配置还是在liquibase脚本中，所以我只发布所有这些。我是否缺少配置？我是否正确配置级联？我的模型定义/liquibase脚本是错误的吗

我在保存父母时遇到的例外是：

Hibernate: insert into parent (name) values (?)
2021-12-15 23:29:16.797  WARN 14115 --- [    Test worker] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 0, SQLState: 23502
2021-12-15 23:29:16.798 ERROR 14115 --- [    Test worker] o.h.engine.jdbc.spi.SqlExceptionHelper   : ERROR: null value in column "id" of relation "parent" violates not-null constraint
Detail: Failing row contains (null, Test 1).
org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [id" of relation "parent]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement
...
Caused by: org.hibernate.exception.ConstraintViolationException: could not execute statement
...
Caused by: org.postgresql.util.PSQLException: ERROR: null value in column "id" of relation "parent" violates not-null constraint
Detail: Failing row contains (null, Test 2).

我试图运行的代码：

val parent = Parent(
id = 0,
name = "Test 2"
).apply {
children = mutableSetOf(
Child(
id = 0,
name = "Test 21",
parent = this
).apply {
grandchildren =
mutableSetOf(
Grandchild(
id = 0,
name = "Test 211",
child = this
)
)
},
Child(
id = 0,
name = "Test 22",
parent = this
)
)
}
val saveParent: Parent = parentRepository.save(parent)

型号：

@Entity
class Parent(
@Id @GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Long = 0,
var name: String,
@OneToMany(mappedBy = "parent", cascade = [CascadeType.ALL])
var children: MutableSet<Child> = mutableSetOf()
)

@Entity
class Child(
@Id @GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Long = 0,
var name: String,
@ManyToOne @JoinColumn(name = "child_id")
var parent: Parent,
@OneToMany(mappedBy = "child", cascade = [CascadeType.ALL])
var grandchildren: MutableSet<Grandchild> = mutableSetOf()
)

@Entity
class Grandchild(
@Id @GeneratedValue(strategy = GenerationType.IDENTITY)
var id: Long = 0,
var name: String,
@ManyToOne @JoinColumn(name = "child_id")
var child: Child
)

application.yml

spring:
datasource:
platform: postgres
url: jdbc:postgresql://localhost:5432/onetomany?ssl=false
driver-class-name: org.postgresql.Driver
initialization-mode: always
jpa:
database: postgresql
database-platform: org.hibernate.dialect.PostgreSQLDialect
generate-ddl: false
hibernate:
ddl-auto: none
liquibase:
enabled: true
change-log: classpath:db/master.xml

liquibase脚本：

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-4.1.xsd">
<changeSet author="bruce (generated)" id="data-1">
<createTable tableName="parent">
<column name="id" type="BIGINT">
<constraints nullable="false" primaryKey="true" primaryKeyName="PK_PARENT"/>
</column>
<column name="name" type="VARCHAR(255)">
<constraints nullable="false"/>
</column>
</createTable>
</changeSet>
<changeSet author="bruce (generated)" id="data-2">
<createTable tableName="child">
<column name="id" type="BIGINT">
<constraints nullable="false" primaryKey="true" primaryKeyName="PK_CHILD"/>
</column>
<column name="name" type="VARCHAR(255)">
<constraints nullable="false"/>
</column>
<column name="parent_id" type="BIGINT">
<constraints nullable="false"/>
</column>
</createTable>
</changeSet>
<changeSet author="bruce (generated)" id="data-3">
<createTable tableName="grandchild">
<column name="id" type="BIGINT">
<constraints nullable="false" primaryKey="true" primaryKeyName="PK_GRANDCHILD"/>
</column>
<column name="name" type="VARCHAR(255)">
<constraints nullable="false"/>
</column>
<column name="child_id" type="BIGINT">
<constraints nullable="false"/>
</column>
</createTable>
</changeSet>
<changeSet author="bruce (generated)" id="data-6">
<addForeignKeyConstraint baseColumnNames="parent_id" baseTableName="child" constraintName="FK_CHILD_PARENT"
deferrable="false" initiallyDeferred="false" onDelete="RESTRICT" onUpdate="RESTRICT"
referencedColumnNames="id" referencedTableName="parent" validate="true"/>
</changeSet>
<changeSet author="bruce (generated)" id="data-8">
<addForeignKeyConstraint baseColumnNames="child_id" baseTableName="grandchild" constraintName="FK_CHILD_GRANDCHILD"
deferrable="false" initiallyDeferred="false" onDelete="RESTRICT" onUpdate="RESTRICT"
referencedColumnNames="id" referencedTableName="child" validate="true"/>
</changeSet>
</databaseChangeLog>

Answer 1

@GeneratedValue(strategy = GenerationType.IDENTITY)通常通过在数据库中指定自动递增的默认值来工作，例如nextval('my_entity_sequence'::regclass)。插入后，DB将生成标识符。

在Postgres中，有serial/bigserial伪类型来指定自动递增列(它将在内部创建序列和列默认值(，因此DDL可能如下所示：
create table my_entity ( id bigserial not null, primary key (id) )
https://www.postgresql.org/docs/current/datatype-numeric.html

在您的案例中，likibase错过了所有ID列的类型/默认值(现在只有"父"-插入失败，但其他实体的插入也会失败(。

这是一个已知的利口酒问题：https://github.com/liquibase/liquibase/issues/1009-解决此问题的建议包括在变更集中手动指定autoIncrement="true"。