Database.Neo4j.Graph

Module to handle Graph objects. These have information about a group of nodes, relationships, and information about labels per node and nodes per label. Notice a graph can have relationships and at the same time not have some of the nodes of those relationships, see the section called handling orphaned relationships. This is so because commands in a batch might retrieve relationships but might not create or retrieve their respective nodes.

General objects

data Graph

Instances

Eq Graph

Show Graph

type LabelSet = HS.HashSet Label

empty :: Graph

Create an empty graph

Handling nodes in the graph object

addNode :: Node -> Graph -> Graph

Add a node to the graph

hasNode :: NodeIdentifier a => a -> Graph -> Bool

Whether a node is present in the graph

deleteNode :: NodeIdentifier a => a -> Graph -> Graph

Delete a node from the graph

getNodes :: Graph -> [Node]

Get a list with all the nodes in the graph

getNode :: NodeIdentifier a => a -> Graph -> Maybe Node

Get a node in the graph

getNodeFrom :: NodeIdentifier a => a -> Graph -> Maybe [Relationship]

Get outgoing relationships from a node

getNodeTo :: NodeIdentifier a => a -> Graph -> Maybe [Relationship]

Get incoming relationships from a node

Handling properties in the graph object

getRelationships :: Graph -> [Relationship]

Get a list with all the relationships in the graph

hasRelationship :: RelIdentifier a => a -> Graph -> Bool

Whether a relationship is present in the graph

addRelationship :: Relationship -> Graph -> Graph

Add a relationship to the graph

deleteRelationship :: RelIdentifier a => a -> Graph -> Graph

Delete a relationship from the graph

getRelationshipNodeFrom :: Relationship -> Graph -> Maybe Node

Get the node from from a relationship

getRelationshipNodeTo :: Relationship -> Graph -> Maybe Node

Get the node to from a relationship

getRelationship :: RelIdentifier a => a -> Graph -> Maybe Relationship

Get a relationship in the graph

Handling orphaned relationships

getOrphansFrom :: Graph -> [Relationship]

Get relationships missing their from node

getOrphansTo :: Graph -> [Relationship]

Get relationships missing their to node

cleanOrphanRelationships :: Graph -> Graph

Remove all relationships with a missing node

Handling properties

setProperties :: EntityIdentifier a => a -> Properties -> Graph -> Graph

Set the properties of a node or relationship in the graph, if not present it won't do anything

setProperty :: EntityIdentifier a => a -> Text -> PropertyValue -> Graph -> Graph

Set a property of a node or relationship in the graph, if not present it won't do anything

deleteProperties :: EntityIdentifier a => a -> Graph -> Graph

Delete all the properties of a node or relationship, if the entity is not present it won't do anything

deleteProperty :: EntityIdentifier a => a -> Text -> Graph -> Graph

Delete a property of a node or relationship, if the entity is not present it won't do anything

Handling labels

setNodeLabels :: NodeIdentifier a => a -> [Label] -> Graph -> Graph

Set what labels a node has

addNodeLabel :: NodeIdentifier a => a -> Label -> Graph -> Graph

Add a label to a node

getNodeLabels :: NodeIdentifier a => a -> Graph -> LabelSet

Get the labels of a node

deleteNodeLabel :: NodeIdentifier a => a -> Label -> Graph -> Graph

Remove a label from a node

Handling Cypher results

addCypher :: Response -> Graph -> Graph

Feed a cypher result (from the old API) into a graph (looks for nodes and relationships and inserts them)

Graph filtering functions

nodeFilter :: (Node -> Bool) -> Graph -> Graph

Filter the nodes of a graph

relationshipFilter :: (Relationship -> Bool) -> Graph -> Graph

Filter the relationships of a graph

Graph operations

union :: Graph -> Graph -> Graph

Add two graphs resulting in a graph with all the nodes, labels and relationships of both | If a node/entity is present in both the second one will be chosen

difference :: Graph -> Graph -> Graph

Remove the nodes and relationships in the first graph that appear in the second

intersection :: Graph -> Graph -> Graph

Have a graph that only has nodes and relationships that are present in both