Question

以下是两个节点实体

User.java

@NodeEntity
public class User {
    @GraphId
    private Long id;

    private String firstName;
    private String lastName;

    @Fetch @RelatedTo(type = "HAS_ROLE")
    private Role role;
    ...

}

Role.java

@NodeEntity
public class Role {

    @GraphId
    private Long id;
    private User user;
    private Integer role;
        ...
}

如果我想让lastName的用户是“Lin”，我该如何在我的存储库中编写查询？下面是我所做的，但它失败了......

@Query( "Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user")
Iterable<User> getUserLin();

错误讯息是

org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user; nested exception is org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user; nested exception is expected 'START'
"Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user"
 ^
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.query(CypherQueryEngine.java:56)
    at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.dispatchQuery(GraphRepositoryQuery.java:91)
    at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.execute(GraphRepositoryQuery.java:70)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:302)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
    at com.sun.proxy.$Proxy29.getUserLin(Unknown Source)
    at org.krams.service.UserService.getUserLin(UserService.java:32)
    at org.krams.service.UserService$$FastClassByCGLIB$$fcd59419.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:698)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.aop.interceptor.CustomizableTraceInterceptor.invokeUnderTrace(CustomizableTraceInterceptor.java:257)
    at org.springframework.aop.interceptor.AbstractTraceInterceptor.invoke(AbstractTraceInterceptor.java:111)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)
    at org.krams.service.UserService$$EnhancerByCGLIB$$5d141efb.getUserLin(<generated>)
    at org.krams.service.test.UserServiceTester.getUserLinIterTester(UserServiceTester.java:36)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:88)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user; nested exception is expected 'START'
"Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user"
 ^
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.parseAndExecuteQuery(CypherQueryEngine.java:67)
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.query(CypherQueryEngine.java:53)
    ... 51 more
Caused by: expected 'START'
"Match user-[:HAS_ROLE]-role where user.lastName = 'Lin' return user"
 ^
    at org.neo4j.cypher.internal.parser.v1_6.CypherParserImpl.parse(CypherParserImpl.scala:65)
    at org.neo4j.cypher.CypherParser.parse(CypherParser.scala:42)
    at org.neo4j.cypher.ExecutionEngine$$anonfun$prepare$1.apply(ExecutionEngine.scala:60)
    at org.neo4j.cypher.ExecutionEngine$$anonfun$prepare$1.apply(ExecutionEngine.scala:60)
    at org.neo4j.cypher.internal.LRUCache.getOrElseUpdate(LRUCache.scala:31)
    at org.neo4j.cypher.ExecutionEngine.prepare(ExecutionEngine.scala:60)
    at org.neo4j.cypher.ExecutionEngine.execute(ExecutionEngine.scala:54)
    at org.neo4j.cypher.ExecutionEngine.execute(ExecutionEngine.scala:57)
    at org.neo4j.cypher.javacompat.ExecutionEngine.execute(ExecutionEngine.java:86)
    at org.springframework.data.neo4j.support.query.CypherQueryEngine.parseAndExecuteQuery(CypherQueryEngine.java:65)
    ... 52 more

我是否应该在Spring Data Neo4j中使用“START node ... MATCH relationship ... RETURN ...”？如果以下查询将成功：

@Query( "start user=node:User(username={0}) match user-[:HAS_ROLE]-role return user")
User getUserLin(String username);

如果删除关系并“开始”，它将会失败...为什么？ {0}中的(username={0})表示User getUserLin(String username)的第一个参数？

@Query( "match user where user.username='John' return user")
User getUserLin();

Answer 1

您可能使用旧版本的Spring Data Neo4j MATCH ...语法仅支持3.x

Spring Data Neo4j中简单自定义查询的错误

1 个答案: