1

如何选择与 Spring Data JDBC 的一对一关系中的引用实体？

当我在此博客上尝试以下代码时

class PurchaseOrder {

    @Id
    private Long id;
    private String shippingAddress;
    private Set<OrderItem> items;
}

class OrderItem {

    @Id
    private Long id;
    private int quantity;
    private String product;
}

@Test
void test() {
    PurchaseOrder purchaseOrder = PurchaseOrder.of("Tokyo");
    purchaseOrder.addItem(4, "Captain Future Comet Lego set");
    purchaseOrder.addItem(2, "Cute blue angler fish plush toy");
    orderRepository.save(purchaseOrder);

    Iterable<PurchaseOrder> result = orderRepository.findAll(); //throw MappingException !!
    result.forEach(System.out::println);
}

这会在下面引发异常：

org.springframework.data.mapping.MappingException: Could not read property @org.springframework.data.annotation.Id()private final java.lang.Long com.example.demo.OrderItem.id from result set!

    at org.springframework.data.jdbc.core.EntityRowMapper.readFrom(EntityRowMapper.java:130)
    at org.springframework.data.jdbc.core.EntityRowMapper.readEntityFrom(EntityRowMapper.java:143)
    at org.springframework.data.jdbc.core.EntityRowMapper.readFrom(EntityRowMapper.java:124)
    at org.springframework.data.jdbc.core.EntityRowMapper.lambda$createInstance$0(EntityRowMapper.java:167)
......
Caused by: org.h2.jdbc.JdbcSQLException: Column "items_id" not found [42122-197]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:357)
    at org.h2.message.DbException.get(DbException.java:179)
    at org.h2.message.DbException.get(DbException.java:155)
......

从 ResultSet 检索值时，spring data jdbc 将父实体的名称作为前缀添加到子实体的列中。但是我不能在文档上使用这个映射规则......

有没有办法自定义这个映射规则？

DDL：

create table purchase_order (
  id bigint primary key auto_increment,
  shipping_address varchar NOT NULL
);

create table order_item (
  id bigint primary key auto_increment,
  purchase_order bigint NOT NULL,
  quantity int NOT NULL,
  product varchar NOT NULL
);

[更新]

spring-data-jdbc 的版本是 1.0.4.RELEASE。

SQL 语句在这里：

2019-01-29 23:49:16.932 DEBUG 80409 --- [           main] o.s.jdbc.core.JdbcTemplate               : Executing prepared SQL statement [SELECT purchase_order.id AS id, purchase_order.shipping_address AS shipping_address FROM purchase_order]

完整的堆栈跟踪是

org.springframework.data.mapping.MappingException: Could not read property @org.springframework.data.annotation.Id()private java.lang.Long com.example.demo.OrderItem.id from result set!

    at org.springframework.data.jdbc.core.EntityRowMapper.readFrom(EntityRowMapper.java:130)
    at org.springframework.data.jdbc.core.EntityRowMapper.readEntityFrom(EntityRowMapper.java:143)
    at org.springframework.data.jdbc.core.EntityRowMapper.readFrom(EntityRowMapper.java:124)
    at org.springframework.data.jdbc.core.EntityRowMapper.lambda$createInstance$0(EntityRowMapper.java:167)
    at org.springframework.data.relational.core.conversion.BasicRelationalConverter$ConvertingParameterValueProvider.getParameterValue(BasicRelationalConverter.java:251)
    at org.springframework.data.convert.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:75)
    at org.springframework.data.convert.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:84)
    at org.springframework.data.relational.core.conversion.BasicRelationalConverter.createInstance(BasicRelationalConverter.java:141)
    at org.springframework.data.jdbc.core.EntityRowMapper.createInstance(EntityRowMapper.java:160)
    at org.springframework.data.jdbc.core.EntityRowMapper.mapRow(EntityRowMapper.java:71)
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:94)
    at org.springframework.jdbc.core.RowMapperResultSetExtractor.extractData(RowMapperResultSetExtractor.java:61)
    at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:679)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:617)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:669)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:694)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:748)
    at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:215)
    at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:227)
    at org.springframework.data.jdbc.core.DefaultDataAccessStrategy.findAll(DefaultDataAccessStrategy.java:217)
    at org.springframework.data.jdbc.core.JdbcAggregateTemplate.findAll(JdbcAggregateTemplate.java:158)
    at org.springframework.data.jdbc.repository.support.SimpleJdbcRepository.findAll(SimpleJdbcRepository.java:84)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:359)
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:644)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:608)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
    at com.sun.proxy.$Proxy68.findAll(Unknown Source)
    at com.example.demo.OrderRepositoryTest.test(OrderRepositoryTest.java:61)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:532)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:171)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:167)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:114)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:59)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:108)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:220)
    at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:188)
    at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:202)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:181)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.h2.jdbc.JdbcSQLException: Column "items_id" not found [42122-197]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:357)
    at org.h2.message.DbException.get(DbException.java:179)
    at org.h2.message.DbException.get(DbException.java:155)
    at org.h2.jdbc.JdbcResultSet.getColumnIndex(JdbcResultSet.java:3174)
    at org.h2.jdbc.JdbcResultSet.get(JdbcResultSet.java:3247)
    at org.h2.jdbc.JdbcResultSet.getObject(JdbcResultSet.java:529)
    at org.springframework.data.jdbc.core.EntityRowMapper.readFrom(EntityRowMapper.java:127)
    ... 86 more
4

1 回答 1

0

以下是从官方文档中复制的。

总结一下：Spring Data JDBC 不支持多对一或多对多关系。为了对这些进行建模，请使用 ID。这鼓励了域模型的干净模块化。它还消除了人们必须解决并学习推理这种映射是否可能的一整类问题。

 class PurchaseOrder {

   @Id
   private Long id;
   private String shippingAddress;
  private Set<OrderItem> items;

     private OrderItemRef createOrderItem(OrderItem orderItem ) {

   OrderItemRef orderItemRef = new OrderItemRef ();
   orderItemRef.orderItem = orderItemRef.id;
   return orderItemRef ;
 }
 }

  @Table("Purchase_OrderItem ")
class OrderItemRef {
    Long orderItem;
 }


 class OrderItem {

   @Id
  private Long id;
  private int quantity;
  private String product;
 }
于 2019-01-29T09:44:15.420 回答