修改或更改py2neo中的关系属性 [英] Modify or change relationship properties in py2neo

问题描述

使用py2neo或cypher设置关系属性后，是否可以更改它?我正在创建一个库存跟踪器，一旦项目为"CHECKED_OUT"，则关系中的一个名为"status"的属性将设置为"True".理想情况下，一旦退回或签入商品，我想将"status"属性更改为"False".这样，我就可以跟踪该项目，并防止它被两次检出.

Is there a way to change a relationship property once it has been set using py2neo or cypher? I'm creating an inventory tracker and once an item is "CHECKED_OUT" a property called "status" in the relationship is set to "True". Ideally, once the item is returned or checked in, I'd like to change the "status" property to "False". This way I can keep track of the item and prevent it from being checked out twice.

这是我为结帐交易创建关系的代码:

Here is my code for creating the relationship for a checkout transaction:

    def check_out(self, barcode):
        emp = self
        item = barcode
        id = str(uuid.uuid4())
        timestamp = int(datetime.now().strftime("%s"))
        date = datetime.now().strftime("%F")
        status=True
        rel = Relationship(emp, "CHECKED_OUT", item, id=id, timestamp=timestamp, date=date, status=status)
        if not(graph.create_unique(rel)):
            return True
        else:
            return False

我已经阅读了py2neo API，但似乎找不到答案.如果修改关系是错误的方法，您能提供更好的方法吗?

I've read through the py2neo API and I can't seem to find the answer. If modifying the relationship is the wrong approach, can you offer a better one?

推荐答案

与此类似的方法应该起作用:

Something along this line should work:

def check_in(self, barcode):
    item = barcode

    # get the relationship
    for rel in graph.match(start_node=self, rel_type="CHECKED_OUT", end_node=item):
        # set property
        rel.properties["status"] = False
        rel.push()

请参见match(): http://py2neo.org/2.0/essentials .html#py2neo.Graph.match

和properties: http://py2neo.org/2.0/essentials .html#py2neo.Relationship.properties

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