Question

Neo4jOperations#queryForObjects()似乎与@QueryResult POJO无关 - 它始终表示结果集为空。

尝试Neo4jOperations#queryForObjects - 它说结果为空：

@Test
public void thisDoesNotWork() {
    Iterable<ClassNodeIdAndName> result = neo4jOperations.queryForObjects(
            ClassNodeIdAndName.class,
            "MATCH (c:ClassNode) RETURN ID(c) AS id, c.name AS name",
            new HashMap<>());
    assertTrue(result.iterator().hasNext());
}

尝试Neo4jOperations#query - 说结果不为空：

@Test
public void thisWorksFine() {
    Result result = neo4jOperations.query(
            "MATCH (c:ClassNode) RETURN ID(c) AS id, c.name AS name",
            new HashMap<>());
    assertTrue(result.iterator().hasNext());
}

尝试使用@Query存储库 - 说结果不为空：

@Test
public void thisWorksFineAsWell() {
    List<ClassNodeIdAndName> classNodeIdsAndNames = classNodeRepository.getAllIdsAndNames();
    assertFalse(classNodeIdsAndNames.isEmpty());
}

public interface ClassNodeRepository extends GraphRepository<ClassNode> {
    @Query("MATCH (c:ClassNode) RETURN ID(c) AS id, c.name AS name")
    List<ClassNodeIdAndName> getAllIdsAndNames();
}

@QueryResult
public class ClassNodeIdAndName {
    public Long id;
    public String name;
}

Documentation说

Iterable queryForObjects（Class entityType ，

entityType - 表示要返回的实体类型的类

但我很困惑我是应该查看实体类型还是查看对象。如果它不应该处理@QueryResult，我会指望它抛出而不是没有返回任何结果。

我使用的是spring-data-neo4j 4.1.3.RELEASE

Answer 1

#define ALPHABETS_COUNT 26 int commonChars(char *s1, char *s2) { int c_count = 0, i; int arr1[ALPHABETS_COUNT] = {0}, arr2[ALPHABETS_COUNT] = {0}; /* Compute the number of occurances of each character */ while (*s1) arr1[*s1++-'a'] += 1; while (*s2) arr2[*s2++-'a'] += 1; /* Increment count based on match found */ for(i=0; i<ALPHABETS_COUNT; i++) { if(arr1[i] == arr2[i]) c_count += arr1[i]; else if(arr1[i]>arr2[i] && arr2[i] != 0) c_count += arr2[i]; else if(arr2[i]>arr1[i] && arr1[i] != 0) c_count += arr1[i]; } return c_count;是Spring Data Neo4j概念，仅适用于Spring @QueryResult。

Repository是Neo4j OGM Neo4jOperations类的一个瘦包装器，因此不处理返回查询结果对象的概念。

另见：SDN 4 Session.query doesn't work for @QueryResult

我是否应该期望Neo4jOperations＃queryForObjects与@QueryResult POJO一起使用？

1 个答案: