java 遍历框架中的 neo4j 密码查询
neo4j cypher query in java traversal framework
我有一个密码查询,它总结了每个 child 的数量并将这个总和设置到 parent 节点。
MATCH (n:product)-[:COSTS*0..]->(child) WITH n, sum(child.amount) as sum SET n.costs=sum;
product1(amount:20) -[:COSTS]-> product2(amount:10)
product2 -[:COSTS]-> product3(amount:5)
product2 -[:COSTS]-> product4(amount:7)
所以我的产品的结果是:
product1.costs = 42
product2.costs = 22
有人可以提示我如何使用 java 中的 neo4j 遍历框架吗?
我正在使用 neo4j 版本 2.2.5 和核心版本 2.2.5 api for neo4j。
这是我对您问题的处理方法
数据
CREATE (p1:Product {id: 1, amount: 30}),
(p2:Product {id: 2, amount: 20}),
(p3:Product {id: 3, amount: 10}),
(p4:Product {id: 4, amount: 40}),
(p1)-[:COSTS]->(p2),
(p2)-[:COSTS]->(p3),
(p2)-[:COSTS]->(p4)
代码
try (Transaction tx = getDatabase().beginTx()) {
GraphDatabaseService database = getDatabase();
Node rootProduct = database.findNode(DynamicLabel.label("Product"), "id", 1);
int sum = getChildrenSum(rootProduct);
rootProduct.setProperty("costs", sum);
tx.success();
}
public int getChildrenSum(Node product) {
int sum = 0;
final DynamicRelationshipType relationshipType = DynamicRelationshipType.withName("COSTS");
final Direction direction = Direction.OUTGOING;
if (product.hasRelationship(relationshipType, direction)) {
for (Relationship costs : product.getRelationships(relationshipType, direction)) {
final Node child = costs.getEndNode();
final String propertyName = "amount";
if (child.hasProperty(propertyName)) {
sum += Integer.parseInt(child.getProperty(propertyName).toString());
}
childrenSum += getChildrenSum(child);
sum += childrenSum;
child.setProperty("costs", childrenSum);
}
}
return sum;
}
我有一个密码查询,它总结了每个 child 的数量并将这个总和设置到 parent 节点。
MATCH (n:product)-[:COSTS*0..]->(child) WITH n, sum(child.amount) as sum SET n.costs=sum;
product1(amount:20) -[:COSTS]-> product2(amount:10)
product2 -[:COSTS]-> product3(amount:5)
product2 -[:COSTS]-> product4(amount:7)
所以我的产品的结果是:
product1.costs = 42
product2.costs = 22
有人可以提示我如何使用 java 中的 neo4j 遍历框架吗?
我正在使用 neo4j 版本 2.2.5 和核心版本 2.2.5 api for neo4j。
这是我对您问题的处理方法
数据
CREATE (p1:Product {id: 1, amount: 30}),
(p2:Product {id: 2, amount: 20}),
(p3:Product {id: 3, amount: 10}),
(p4:Product {id: 4, amount: 40}),
(p1)-[:COSTS]->(p2),
(p2)-[:COSTS]->(p3),
(p2)-[:COSTS]->(p4)
代码
try (Transaction tx = getDatabase().beginTx()) {
GraphDatabaseService database = getDatabase();
Node rootProduct = database.findNode(DynamicLabel.label("Product"), "id", 1);
int sum = getChildrenSum(rootProduct);
rootProduct.setProperty("costs", sum);
tx.success();
}
public int getChildrenSum(Node product) {
int sum = 0;
final DynamicRelationshipType relationshipType = DynamicRelationshipType.withName("COSTS");
final Direction direction = Direction.OUTGOING;
if (product.hasRelationship(relationshipType, direction)) {
for (Relationship costs : product.getRelationships(relationshipType, direction)) {
final Node child = costs.getEndNode();
final String propertyName = "amount";
if (child.hasProperty(propertyName)) {
sum += Integer.parseInt(child.getProperty(propertyName).toString());
}
childrenSum += getChildrenSum(child);
sum += childrenSum;
child.setProperty("costs", childrenSum);
}
}
return sum;
}