[英]Unable to change or delete relationship between nodes with Neo4j OGM and Spring Boot Data
[英]Spring Data Neo4j 4.0.0: Can't Create Relationship Between Nodes with the Same Label
我正在使用帶有Neo4j 2.2.1的Spring Data Neo4j 4.0.0,並且我正在嘗試使用完全相同的標簽在兩個節點之間創建關系。
因此,我有一個NodeEntity類,並且內部有一個與類本身具有相同Type的變量,並將其注釋為Relationship。 但是,當我使用存儲庫對象的save()方法將對象保存到數據庫時,無法創建關系。
在此先感謝您,您的建議將不勝感激!
編輯
這是節點實體類
public class ArchitectureUnitState extends UnitState {
public ArchitectureUnitState()
{
super();
}
public ArchitectureUnitState(String name, String description, String parentArchitectureUnitName)
{
super(name, description);
this.parentArchitectureUnitName = parentArchitectureUnitName;
}
@Relationship(type="PART_OF", direction = Relationship.OUTGOING)
private ArchitectureUnitState architectureUnitState;
@Relationship(type="STATE_OF", direction = Relationship.OUTGOING)
private ArchitectureUnit architectureUnit;
@Transient
private String parentArchitectureUnitName;
public void partOf(ArchitectureUnitState architectureUnitState) {
this.architectureUnitState = architectureUnitState;
}
public void stateOf(ArchitectureUnit architectureUnit) {
this.architectureUnit = architectureUnit;
}
public void childOf(String parentArchitectureUnitName) {
this.parentArchitectureUnitName = parentArchitectureUnitName;
}
public String getParentName() {
return parentArchitectureUnitName;
}
}
@NodeEntity
public class UnitState {
@GraphId
protected Long id;
private String name;
private String description;
public UnitState() {
}
public UnitState(String name, String description) {
this.name = name;
this.description = description;
}
public void setName(String name) {
this.name = name;
}
public void setDescription(String description) {
this.description = description;
}
public String getName() {
return name;
}
public String getDescription() {
return description;
}
}
因此,順序為:我創建了ArchitectureUnitState對象,將它們映射到另一個對象,然后使用ArchitectureUnitStateRepository的save()方法進行保存。
如果我這樣做,盡管在調試中看到值在那里,但不會創建PART_OF關系。
我現在的解決方法是先保存所有ArchitectureUnitState節點,然后再次從數據庫中檢索它們,將它們映射到另一個,然后再次保存。 這樣,可以創建關系,但是我需要保存兩次。
這是我上面使用您的類的測試用例。
@Test
public void testArchitectureState() {
ArchitectureUnitState state1 = new ArchitectureUnitState("one","desc one","root");
ArchitectureUnitState state2 = new ArchitectureUnitState("two","desc two","root");
ArchitectureUnit unit1 = new ArchitectureUnit("unit1");
ArchitectureUnit unit2 = new ArchitectureUnit("unit2");
state1.partOf(state2);
state1.stateOf(unit1);
state2.stateOf(unit2);
architectureUnitStateRepository.save(state1);
state1 = architectureUnitStateRepository.findByName("one");
assertEquals("two", state1.getArchitectureUnitState().getName());
assertEquals("unit1", state1.getArchitectureUnit().getName());
state2 = architectureUnitStateRepository.findByName("two");
assertNull(state2.getArchitectureUnitState());
assertEquals("unit2", state2.getArchitectureUnit().getName());
}
它確實按預期通過,並且在圖中創建的節點似乎指示相同。
注意assertNull(state2.getArchitectureUnitState());
之所以成立,是因為關系的方向指定為OUTGOING。 狀態2沒有傳出的PART_OF關系,因此將不會加載任何關系。
如果我將測試更改為
@Test
public void testArchitectureBothWays() {
ArchitectureUnitState state1 = new ArchitectureUnitState("one","desc one","root");
ArchitectureUnitState state2 = new ArchitectureUnitState("two","desc two","root");
ArchitectureUnit unit1 = new ArchitectureUnit("unit1");
ArchitectureUnit unit2 = new ArchitectureUnit("unit2");
state1.partOf(state2);
state2.partOf(state1);
state1.stateOf(unit1);
state2.stateOf(unit2);
architectureUnitStateRepository.save(state1);
state1 = architectureUnitStateRepository.findByName("one");
assertEquals("two", state1.getArchitectureUnitState().getName());
assertEquals("unit1", state1.getArchitectureUnit().getName());
state2 = architectureUnitStateRepository.findByName("two");
assertEquals("one",state2.getArchitectureUnitState().getName());
assertEquals("unit2", state2.getArchitectureUnit().getName());
}
那么我們在兩個方向上都有關系,現在state2與state1有關系。
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