erreurs de simples requêtes personnalisées au printemps données Neo4j

Question

Voici deux entités de noeud

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; 
     ... 
} 

Si je veux l'utilisateur qui est lastName est "Lin", comment pourrais-je écrire la requête dans mon dépôt? Ci-dessous bloc est ce que je l'ai fait, mais il a échoué ...

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

Le message d'erreur est

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 

Que devrais-je utiliser le noeud « START ... relation MATCH ... RETURN ... "dans Spring Data Neo4j? Si Depuis ci-dessous requête sera succès:

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

Si je supprime la relation et « start », il sera échouer ... pourquoi? Et le {0} dans (username={0}) signifie le premier paramètre de User getUserLin(String username)?

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

Answer 1

Vous utilisez probablement une ancienne version du printemps de données Neo4j la syntaxe MATCH ... est prise en charge dans 3.x