我不知道如何使用orientdb OGM创建一个方法来删除django rest框架中的边缘。
我正在使用pyorient==1.5.5
和OrientDB 3.0.18
版本。
我有两个顶点类:ousers
、ocompany
。我也有两个关系(边)类:ofriends
、oworksat
。所以例如:
要建立ofriends
关系,我需要两个ousers
。 而要建立oworksat
关系,我需要一ouser
一ocompany
。 每个关系都有自己的群集 ID。
我知道我可以访问这些功能:
(Pdb) dir(graph)
['PROPERTY_TYPES', '_GROOVY_GET_DB', '_GROOVY_NULL_LISTENER', '_GROOVY_TRY', 'class', 'delattr', 'dict', 'dir', 'doc', 'eq', 'format', 'ge', 'getattribute', 'gt', 'hash', 'init', 'le', 'lt', 'module', 'ne', 'new', 'reduce', 'reduce_ex', 'repr', 'setattr', 'sizeof', 'str', 'subclasshook', 'weakref', '_last_cred', '_last_db', '_last_user', 'batch', 'both', 'bothE', 'build_mapping', 'clear_registry', 'client', 'coerce_class_names', 'coerce_class_names_to_quoted', 'compute_all_properties', 'config', 'create_all', "create_class", "create_edge", "create_edge_command", "create_function", "create_props_mapping", "create_vertex", "create_vertex_command", "delete_vertex", "delete_vertex_command", "下降", "drop_all", "drop_class", "edge_from_record", "edges_from_records", "element_from_link", "element_from_record", "elements_from_links", "elements_from_records", "出口", "get_edge", "get_element", "get_vertex", "小精灵",">guard_reserved_words">, 'inE', 'in_', 'include', 'init_broker_for_class', 'list_superclasses', 'ocompany', 'ofriends', 'open', 'ousers', 'out', 'outE', 'oworksat', 'populate
', 'property_from_schema', 'props_from_db', 'props_to_db', 'query', 'registry', 'save_element', 'scripts', 'server_version', 'strict', 'toposort_classes', 'valid_element_base', 'vertex_from_record', 'vertexes_from_records']如果我这样做:
graph.delete_vertex("#21:0")
它工作得很好,并删除了 #21:0ouser
顶点行,这是ofriends
和oworskat
关系的一部分,因此,该命令也会删除包含该顶点的关系。显然,我不想删除整个顶点,只想删除特定的边(不是类,只是关系行)。
我想知道是否存在一些像 delete_edge() 这样的命令,但 dir(graph) 并没有告诉我任何相关内容。
settings.py
from pyorient.ogm import Graph, Config
from pyorient.serializations import OrientSerialization
from pyorient.ogm import declarative
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
config = RawConfigParser()
config.read(BASE_DIR + '/settings.ini')
ORIENTDB = {
'NAME': config.get('orientdbConf', 'DB_NAME'),
'USER': config.get('orientdbConf', 'DB_USER'),
'PASSWORD': config.get('orientdbConf', 'DB_PASS'),
'HOST': config.get('orientdbConf', 'DB_HOST'),
'PORT': config.get('orientdbConf', 'DB_PORT'),
}
Config.from_url('plocal://'+ORIENTDB['HOST']+':'+str(ORIENTDB['PORT'])+'/'+ORIENTDB['NAME']+'',''+ORIENTDB['USER']+'', ''+ORIENTDB['PASSWORD']+'',initial_drop=False,serialization_type=OrientSerialization.Binary)
graph = Graph(Config.from_url(''+ORIENTDB['HOST']+'/'+ORIENTDB['NAME']+'',''+ORIENTDB['USER']+'', ''+ORIENTDB['PASSWORD']+'',initial_drop=False))
Node = declarative.declarative_node()
Relationship = declarative.declarative_relationship()
models.py
from core.settings import Node,Relationship,graph
from pyorient.ogm.property import (String, Date, DateTime, Decimal, Double,
Integer, Boolean, EmbeddedMap, EmbeddedSet,Link, UUID)
class OUsers(Node):
element_plural = 'ousers'
postgresql_id=Integer(nullable=False,unique=True)
class OCompany(Node):
element_plural = 'ocompany'
postgresql_id=Integer(nullable=False,unique=True)
class OFriends(Relationship):
label = 'ofriends'
from_postgresql_ouser_id=Integer(nullable=False,unique=True)
to_postgresql_ouser_id=Integer(nullable=False,unique=True)
class OWorksAt(Relationship):
label = 'oworksat'
from_postgresql_ouser_id=Integer(nullable=False,unique=True)
to_postgresql_ocompany_id=Integer(nullable=False,unique=True)
graph.create_all(Node.registry)
graph.create_all(Relationship.registry)
serializers.py
from .models import (OUsers,OCompany,OFriends,OWorksAt)
from rest_framework import serializers
from django.contrib.auth import get_user_model
User = get_user_model()
class OFriendsSerializer(serializers.Serializer):
from_postgresql_ouser_id = serializers.IntegerField()
to_postgresql_ouser_id = serializers.IntegerField()
def create(self, data):
return OFriends.objects.create(**data)
def update(self, instance, data):
instance.from_postgresql_ouser_id = data.get("from_postgresql_ouser_id")
instance.to_postgresql_ouser_id = data.get("to_postgresql_ouser_id")
instance.save()
return instance
class OFriendsSerializer(serializers.Serializer):
from_postgresql_ouser_id = serializers.IntegerField()
to_postgresql_ouser_id = serializers.IntegerField()
def create(self, data):
return OFriends.objects.create(**data)
def update(self, instance, data):
instance.from_postgresql_ouser_id = data.get("from_postgresql_ouser_id")
instance.to_postgresql_ouser_id = data.get("to_postgresql_ouser_id")
instance.save()
return instance
api.py
class OFriendsViewSet(viewsets.ModelViewSet):
def destroy(self, request, *args, **kwargs):
queryset = graph.ofriends.query()
import pdb;pdb.set_trace()
# HERE should be the command
根据 pyorient OGM 文档,该功能从未添加过。我已经在存储库中创建了一个问题。
所以目前,我使用 pyorient 客户端解决了我的问题,带有原始查询:
pyorient_client.py
from core.settings import ORIENTDB
import pyorient
def orientdbConnection():
"""Orientdb client connection"""
client = None
try:
client = pyorient.OrientDB(ORIENTDB['HOST'], int(ORIENTDB['PORT']))
session_id = client.connect( ORIENTDB['USER'], ORIENTDB['PASSWORD'] )
if client.db_exists( ORIENTDB['NAME'], pyorient.STORAGE_TYPE_MEMORY ):
client.db_open( ORIENTDB['NAME'], ORIENTDB['USER'], ORIENTDB['PASSWORD'])
except Exception as e:
print ("[ ERROR ] Fail orientdb connection. Error: " + str(e))
return client
在 api.py
from rest_framework import status
from rest_framework.response import Response
from core.pyorient_client import *
class OFriendsViewSet(viewsets.ModelViewSet):
def destroy(self, request, *args, **kwargs):
client = orientdbConnection()
client.command("delete edge ofriends where @rid = '" + kwargs['pk'] + "'")
return Response(status=status.HTTP_204_NO_CONTENT)
也许这对其他人有用。请注意,我收到 o'friends @rid 作为参数(通过在 swagger UI 中的 DELETE 方法中传递 id)。
自己构造命令的另一种方法是使用Graph.record_delete()
并向其传递要删除的边缘的记录 ID。
下面的代码片段假定db
是OrientDB
的实例,并且rid
保存要删除的链接的记录 ID:
cluster = rid[1:].split(':')[0]
record = rid[1:].split(':')[1]
db.record_delete(cluster, record)
作为侧边栏,我使用OrientDB的次数越多,我就越后悔选择数据库,因为缺乏对Python驱动程序的支持,该驱动程序在功能上不完整,现在也非常过时。