oguzalb / orum

A graph database implementation with Python

Örüm Graph Database

This is a pet project to understand how graph database stuff works

Doesn't have a parser, you will need to translate your query into Python objects and run them

This is how queries should be run (You can see the examples in tests also)

You will need to run the first two examples on the same graph before the other examples to create the first nodes

Example 1: Create nodes

CREATE (you:Person {name:"Oguz"})
CREATE (you:Person {name:"Berker"})

Translates into

from orum import Graph, Create, QNode, Return, Match, Query, Set, Field


graph = Graph()
query1 = Query([
    Create(QNode(alias="you", labels=["Person"], props=dict(name="Oguz"))),
    Create(QNode(alias="friend", labels=["Person"], props=dict(name="Berker"))),
    Return(["you", "friend"])
])
print "GRAPH 1"
print "query result: %s" % graph.query(query1)
print graph

Example 2: Match and Create Nodes Related with Matches

MATCH (you:Person {name:"Oguz"})
MATCH (friend:Person {name:"Berker"})
CREATE (you)-[:KNOWS]->(n:Person {name:"Tuna"}-[:KNOWS]->(friend))
RETURN you, n, friend

Translates into

from orum import Graph, Create, QNode, Return, Match, Query, Set, Field


graph = Graph()
query2 = Query([
    Match(
        QNode(alias="you", labels=["Person"], props=dict(name="Oguz"))),
    Match(
        QNode(alias="friend", labels=["Person"], props=dict(name="Berker"))),
    Create(
        QNode(
            alias="you",
            rels=dict(
                knows=[QNode(
                    alias="middle",
                    props=dict(name="Tuna"),
                    rels=dict(
                        knows=[QNode(alias="friend")])
                )],
            )
        ),
    ),
    Return(["you", "middle", "friend"])
])
print "query result: %s" % graph.query(query2)
print "GRAPH 2"
print graph

Example 3: Match node in the middle

MATCH (you:Person {name:"Oguz"})-[:KNOWS]->(n)-[:KNOWS]->(friend:Person {name:"Berker"})
RETURN n

Translates into

from orum import Graph, Create, QNode, Return, Match, Query, Set, Field

graph = Graph()
...
...
query3 = Query([
Match(
    QNode(
        alias="you",
        rels=dict(
            knows=[QNode(
                alias="middle",
                props=dict(name="Tuna"),
                rels=dict(
                    knows=[QNode(alias="friend")])
            )],
        )
    ),
),
Return(['middle'])
])
print "query result: %s" % self.graph.query(query3)
print "GRAPH 3"
print self.graph

Example 4: Match and Set field of a node

MATCH (you:Person {name:"Oguz"})-[:KNOWS]->(n)-[:KNOWS]->(friend:Person {name:"Berker"})
SET you.expertise = "python dev"
RETURN n

Translates into

from orum import Graph, Create, QNode, Return, Match, Query, Set, Field

graph = Graph()
...
...
query5 = Query([
    Match(
        QNode(
            alias="you",
            rels=dict(
                knows=[QNode(
                    alias="middle",
                    props=dict(name="Tuna"),
                    rels=dict(
                        knows=[QNode(alias="friend")])
                )],
            )
        ),
    ),
    Set(
        Field(
            alias='you',
            field_name='expertise'
        ),
        'python dev'
    ),
    Return(['middle'])
])
print "query result: %s" % self.graph.query(query5)
print "GRAPH 5"
print self.graph