Database.Bolt.Extras.Graph

This module defines everything needed to make template graph requests to Neo4j.

There are two types of queries that you can run: queries that return something from the database (Get) and queries that save new data to it (Put). Both types are abstracted via type class GraphQuery. Most of the time you will need only its makeRequest method.

Get and Put queries are simply two instances of GraphQuery, differentiated by empty data types GetRequest and PutRequest. This means that you will have to use TypeApplications to call GraphQuery methods, like this:

makeRequest @GetRequest ...

All queries are built from simple templates that can be customized with endomorphisms (things of type a -> a, like the Builder pattern in OOP). Endomorphisms can be conveniently applied using & operator.

A complete example of running Get and Put queries can be found in "example/Main.hs" file in this repository.

Graph template construction

Both query types require a Graph type. Preffered way to create a variable of this type is to start with emptyGraph and add required nodes and relations with addNode and addRelation function.

For example (using Text as node data for simplicity):

queryG :: Graph Text Text Text
queryG = emptyGraph
  & addNode "a" "node a"
  & addNode "b" "node b
  & addRelation "a" "b" "relation a -> b"

data Graph n a b

Representation of Graph that is used for requests and responses. It is parameterized by three types:

• n: type of node names
• a: type of nodes
• b: type of relations

Relations are described by a pair of nodes - start and end.

There are lenses defined for Graph: vertices and relations.

Constructors

Graph

Fields

• _vertices :: Map n a
• _relations :: Map (n, n) b

Instances

(Show n, Show a, Show b) => Show (Graph n a b)

Defined in Database.Bolt.Extras.Graph.Internal.AbstractGraph

Methods

showsPrec :: Int -> Graph n a b -> ShowS

show :: Graph n a b -> String

showList :: [Graph n a b] -> ShowS

Generic (Graph n a b)

Defined in Database.Bolt.Extras.Graph.Internal.AbstractGraph

Associated Types

type Rep (Graph n a b) :: Type -> Type

Methods

from :: Graph n a b -> Rep (Graph n a b) x

to :: Rep (Graph n a b) x -> Graph n a b

type Rep (Graph n a b)

Defined in Database.Bolt.Extras.Graph.Internal.AbstractGraph

type Rep (Graph n a b) = D1 (MetaData "Graph" "Database.Bolt.Extras.Graph.Internal.AbstractGraph" "hasbolt-extras-0.0.0.25-KjoBNmzeYU17gw63Ezn6Ez" False) (C1 (MetaCons "Graph" PrefixI True) (S1 (MetaSel (Just "_vertices") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Map n a)) :*: S1 (MetaSel (Just "_relations") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Map (n, n) b))))

vertices :: forall n a b a. Lens (Graph n a b) (Graph n a b) (Map n a) (Map n a)

relations :: forall n a b b. Lens (Graph n a b) (Graph n a b) (Map (n, n) b) (Map (n, n) b)

emptyGraph :: Ord n => Graph n a b

An empty graph.

addNode

Arguments

:: (Show n, Ord n)

=> n

Name of the node

-> a

Node data

-> Graph n a b

-> Graph n a b

Adds node to graph by its name and data. If graph already contains node with given name, error will be thrown.

addRelation

Arguments

:: (Show n, Ord n)

=> n

Name of start node

-> n

Name of end node

-> b

Relation data

-> Graph n a b

-> Graph n a b

Adds relation to graph by startName of node, endName of node, and rel with relation data. If graph already contains relation with given (startName, endName), error will be thrown.

Get queries

Get queries are represented by GraphGetRequest type - it is a Graph filled with templates for nodes and relations: NodeGetter and RelGetter.

To make a query, you need to build a template of graph that you want to find in the DB. For that, start with empty nodes and relations like defaultNodeReturn and defaultRelReturn. Customize them with endomorphisms in GetterLike class and combine into template graph Graph using emptyGraph, addNode and addRelation.

Typically, a node template is constructed like this:

defaultNodeReturn
  & withLabelQ ''NodeType
  & withBoltId nodeId
  & withReturn allProps

The result of running Get query will be represented as a Graph as well, with GraphGetResponse alias. You can then use convenient functions like extractNode and extractRelation to get your datatypes (that are instances of NodeLike or URelationshipLike) from the result.

Getter types

data GetRequest

Get request with graph result.

Instances

GraphQuery GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

Associated Types

type NodeReq GetRequest :: Type

type RelReq GetRequest :: Type

type NodeRes GetRequest :: Type

type RelRes GetRequest :: Type

Methods

requestEntities :: [(NodeName, NodeReq GetRequest)] -> [((NodeName, NodeName), RelReq GetRequest)] -> (Text, [Text])

formQuery :: [Text] -> Graph NodeName (NodeReq GetRequest) (RelReq GetRequest) -> Text

extractGraphs :: (Extractable (NodeRes GetRequest), Extractable (RelRes GetRequest), MonadIO m) => [NodeName] -> [(NodeName, NodeName)] -> [Record] -> BoltActionT m [Graph NodeName (NodeRes GetRequest) (RelRes GetRequest)]

makeRequest :: (Requestable (NodeName, NodeReq GetRequest), Requestable ((NodeName, NodeName), RelReq GetRequest), Returnable (NodeName, NodeReq GetRequest), Returnable ((NodeName, NodeName), RelReq GetRequest), Extractable (NodeRes GetRequest), Extractable (RelRes GetRequest), MonadIO m) => [Text] -> Graph NodeName (NodeReq GetRequest) (RelReq GetRequest) -> BoltActionT m [Graph NodeName (NodeRes GetRequest) (RelRes GetRequest)]

type NodeReq GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type NodeReq GetRequest = NodeGetter

type RelReq GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type RelReq GetRequest = RelGetter

type NodeRes GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type NodeRes GetRequest = NodeResult

type RelRes GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type RelRes GetRequest = RelResult

class GetterLike a where

Endomorphisms to set up NodeGetter and RelGetter.

Methods

withBoltId

Arguments

:: BoltId

-> a

-> a

set known BoltId

withLabel

Arguments

:: Label

-> a

-> a

set known label

withLabelQ

Arguments

:: Name

-> a

-> a

set known label as TemplateHaskell Name

withProp

Arguments

:: (Text, Value)

-> a

-> a

add known property

withReturn

Arguments

:: [Text]

-> a

-> a

add list of properties to return

isReturned

Arguments

:: a

-> a

set that entity should be returned

Instances

GetterLike RelGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

withBoltId :: BoltId -> RelGetter -> RelGetter

withLabel :: Label -> RelGetter -> RelGetter

withLabelQ :: Name -> RelGetter -> RelGetter

withProp :: (Text, Value) -> RelGetter -> RelGetter

withReturn :: [Text] -> RelGetter -> RelGetter

isReturned :: RelGetter -> RelGetter

GetterLike NodeGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

withBoltId :: BoltId -> NodeGetter -> NodeGetter

withLabel :: Label -> NodeGetter -> NodeGetter

withLabelQ :: Name -> NodeGetter -> NodeGetter

withProp :: (Text, Value) -> NodeGetter -> NodeGetter

withReturn :: [Text] -> NodeGetter -> NodeGetter

isReturned :: NodeGetter -> NodeGetter

data NodeGetter

Helper to find Nodes.

Constructors

NodeGetter

Fields

• ngboltId :: Maybe BoltId

  known BoltId

• ngLabels :: [Label]

  known labels

• ngProps :: Map Text Value

  known properties

• ngReturnProps :: [Text]

  names of properties to return

• ngIsReturned :: Bool

  whether to return this node or not

Instances

Eq NodeGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

(==) :: NodeGetter -> NodeGetter -> Bool

(/=) :: NodeGetter -> NodeGetter -> Bool

Show NodeGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

showsPrec :: Int -> NodeGetter -> ShowS

show :: NodeGetter -> String

showList :: [NodeGetter] -> ShowS

GetterLike NodeGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

withBoltId :: BoltId -> NodeGetter -> NodeGetter

withLabel :: Label -> NodeGetter -> NodeGetter

withLabelQ :: Name -> NodeGetter -> NodeGetter

withProp :: (Text, Value) -> NodeGetter -> NodeGetter

withReturn :: [Text] -> NodeGetter -> NodeGetter

isReturned :: NodeGetter -> NodeGetter

Returnable (NodeName, NodeGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

isReturned' :: (NodeName, NodeGetter) -> Bool

return' :: (NodeName, NodeGetter) -> Text

Requestable (NodeName, NodeGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

request :: (NodeName, NodeGetter) -> Text

data RelGetter

Helper to find URelationships.

Constructors

RelGetter

Fields

• rgboltId :: Maybe BoltId

  known BoltId

• rgLabel :: Maybe Label

  known labels

• rgProps :: Map Text Value

  known properties

• rgReturnProps :: [Text]

  names of properties to return

• rgIsReturned :: Bool

  whether to return this relation or not

Instances

Eq RelGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

(==) :: RelGetter -> RelGetter -> Bool

(/=) :: RelGetter -> RelGetter -> Bool

Show RelGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

showsPrec :: Int -> RelGetter -> ShowS

show :: RelGetter -> String

showList :: [RelGetter] -> ShowS

GetterLike RelGetter

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

withBoltId :: BoltId -> RelGetter -> RelGetter

withLabel :: Label -> RelGetter -> RelGetter

withLabelQ :: Name -> RelGetter -> RelGetter

withProp :: (Text, Value) -> RelGetter -> RelGetter

withReturn :: [Text] -> RelGetter -> RelGetter

isReturned :: RelGetter -> RelGetter

Returnable ((NodeName, NodeName), RelGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

isReturned' :: ((NodeName, NodeName), RelGetter) -> Bool

return' :: ((NodeName, NodeName), RelGetter) -> Text

Requestable ((NodeName, NodeName), RelGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

request :: ((NodeName, NodeName), RelGetter) -> Text

type GraphGetRequest = Graph NodeName NodeGetter RelGetter

The combinations of getters to load graph from the database.

Default getters

defaultNode

Arguments

:: Bool

Whether to return the node

-> NodeGetter

NodeGetter that matches any node.

defaultNodeReturn :: NodeGetter

NodeGetter that matches any node and returns it.

defaultNodeNotReturn :: NodeGetter

NodeGetter that matches any node and does not return it.

defaultRel

Arguments

:: Bool

Whether to return the relation

-> RelGetter

RelGetter that matches any relation.

defaultRelReturn :: RelGetter

RelGetter that matches any relation and returns it.

defaultRelNotReturn :: RelGetter

RelGetter that matches any relation and does not return it.

allProps :: [Text]

Return all properties of a node or relation. To be used with withReturn.

Result types

data NodeResult

Result for node where properties are represented as aeson Value.

Constructors

NodeResult

Fields

• nresId :: BoltId
• nresLabels :: [Label]
• nresProps :: Map Text Value

Instances

Eq NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

(==) :: NodeResult -> NodeResult -> Bool

(/=) :: NodeResult -> NodeResult -> Bool

Show NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

showsPrec :: Int -> NodeResult -> ShowS

show :: NodeResult -> String

showList :: [NodeResult] -> ShowS

Generic NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Associated Types

type Rep NodeResult :: Type -> Type

Methods

from :: NodeResult -> Rep NodeResult x

to :: Rep NodeResult x -> NodeResult

ToJSON NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

toJSON :: NodeResult -> Value

toEncoding :: NodeResult -> Encoding

toJSONList :: [NodeResult] -> Value

toEncodingList :: [NodeResult] -> Encoding

FromJSON NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

parseJSON :: Value -> Parser NodeResult

parseJSONList :: Value -> Parser [NodeResult]

Extractable NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [NodeResult]

GetBoltId NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

getBoltId :: NodeResult -> BoltId

NodeLike NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

toNode :: NodeResult -> Node

fromNode :: Node -> NodeResult

type Rep NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

type Rep NodeResult = D1 (MetaData "NodeResult" "Database.Bolt.Extras.Graph.Internal.Get" "hasbolt-extras-0.0.0.25-KjoBNmzeYU17gw63Ezn6Ez" False) (C1 (MetaCons "NodeResult" PrefixI True) (S1 (MetaSel (Just "nresId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 BoltId) :*: (S1 (MetaSel (Just "nresLabels") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Label]) :*: S1 (MetaSel (Just "nresProps") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Map Text Value)))))

data RelResult

Result for relation where properties are represented as aeson Value.

Constructors

RelResult

Fields

• rresId :: BoltId
• rresLabel :: Label
• rresProps :: Map Text Value

Instances

Eq RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

(==) :: RelResult -> RelResult -> Bool

(/=) :: RelResult -> RelResult -> Bool

Show RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

showsPrec :: Int -> RelResult -> ShowS

show :: RelResult -> String

showList :: [RelResult] -> ShowS

Generic RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Associated Types

type Rep RelResult :: Type -> Type

Methods

from :: RelResult -> Rep RelResult x

to :: Rep RelResult x -> RelResult

ToJSON RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

toJSON :: RelResult -> Value

toEncoding :: RelResult -> Encoding

toJSONList :: [RelResult] -> Value

toEncodingList :: [RelResult] -> Encoding

FromJSON RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

parseJSON :: Value -> Parser RelResult

parseJSONList :: Value -> Parser [RelResult]

Extractable RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [RelResult]

GetBoltId RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

getBoltId :: RelResult -> BoltId

URelationLike RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

toURelation :: RelResult -> URelationship

fromURelation :: URelationship -> RelResult

type Rep RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

type Rep RelResult = D1 (MetaData "RelResult" "Database.Bolt.Extras.Graph.Internal.Get" "hasbolt-extras-0.0.0.25-KjoBNmzeYU17gw63Ezn6Ez" False) (C1 (MetaCons "RelResult" PrefixI True) (S1 (MetaSel (Just "rresId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 BoltId) :*: (S1 (MetaSel (Just "rresLabel") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Label) :*: S1 (MetaSel (Just "rresProps") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Map Text Value)))))

type GraphGetResponse = Graph NodeName NodeResult RelResult

The graph of Nodes and URelationships which we got from the database using GraphGetRequest.

Extracting result

These functions are for extracting nodes and relations in various formats. If an entity does not exist in given GraphGetResponse or is of invalid type, an error will be thrown.

For example, assume you have this query:

  queryG :: GraphGetRequest
  queryG = emptyGraph
    & addNode "exNode"
      (defaultNodeReturn
         & withLabelQ ''ExampleNode
         & withProp   ("exampleFieldT", T A)
         & withReturn allProps
      )

And run it:

result <- makeRequest @GetRequest [] queryG

Then you can get ExampleNode value from the result

let nodes = map extractNode "exNode" result :: [ExampleNode]

You can also just ask for an id of node:

let nodeIds = map extractNodeId "exNode" result

Or, if you did not use withReturn allProps, you can use extractNodeAeson to get raw NodeResult value and inspect its properties.

extractNode :: NodeLike a => NodeName -> GraphGetResponse -> a

Extract a node by its name from GraphGetResponse and convert it to user type with fromNode.

extractRelation :: URelationLike a => NodeName -> NodeName -> GraphGetResponse -> a

Extract a relation by name of it start and end nodes and convert to user type with fromURelation.

extractNodeId :: NodeName -> GraphGetResponse -> BoltId

Extract just node's BoltId.

extractRelationId :: NodeName -> NodeName -> GraphGetResponse -> BoltId

Extract just relation's BoltId.

extractNodeAeson :: NodeName -> GraphGetResponse -> NodeResult

Extract NodeResult.

extractRelationAeson :: NodeName -> NodeName -> GraphGetResponse -> RelResult

Extract RelResult.

mergeGraphs :: GetBoltId a => [Graph NodeName a b] -> Graph NodeName a b

Helper function to merge graphs of results, i.e. if you requested graph A -> B -> C and in the database there were two B entities connected to the same entity A and four C entities connected to the same two entities B, Cypher query will return four graphs which satisfy this path, despite the fact that A was present only once in the database and B was present only two times in the database.

This function will merge these four graphs in one and return nodes by node names with suffixes equal to their BoltIds.

For example, if there were four graphs:

  nodes: [A (boltId = 0), B (boltId = 1), C (boltId = 3)], relations: [A -> B, B -> C];
  nodes: [A (boltId = 0), B (boltId = 1), C (boltId = 4)], relations: [A -> B, B -> C];
  nodes: [A (boltId = 0), B (boltId = 2), C (boltId = 5)], relations: [A -> B, B -> C];
  nodes: [A (boltId = 0), B (boltId = 2), C (boltId = 6)], relations: [A -> B, B -> C].

this function will merge them into new graph:

  nodes: [A0 (boltId = 0), B1 (boltId = 1), B2 (boltId = 2),
          C3 (boltId = 3), C4 (boltId = 4), C5 (boltId = 5), C6 (boltId = 6)],
  relations: [A0 -> B1, A0 -> B2, B1 -> C3, B1 -> C4, B2 -> C5, B2 -> C6].

Put queries

Put queries are represented with GraphPutRequest - a Graph of PutNode and PutRelationship. Build your graph the same way as with Get queryб representing new nodes and relations as PutNode and PutRelationship. The query graph may also describe existing nodes and relations, for example if you need to find a specific node in graph and attach a new one to it, or update an existing node with new data.

Result of Put query will be graph with Neo4j ids of inserted data.

data PutRequest

Put request in Bolt format with BoltIds of uploaded entities as result.

Instances

GraphQuery PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

Associated Types

type NodeReq PutRequest :: Type

type RelReq PutRequest :: Type

type NodeRes PutRequest :: Type

type RelRes PutRequest :: Type

Methods

requestEntities :: [(NodeName, NodeReq PutRequest)] -> [((NodeName, NodeName), RelReq PutRequest)] -> (Text, [Text])

formQuery :: [Text] -> Graph NodeName (NodeReq PutRequest) (RelReq PutRequest) -> Text

extractGraphs :: (Extractable (NodeRes PutRequest), Extractable (RelRes PutRequest), MonadIO m) => [NodeName] -> [(NodeName, NodeName)] -> [Record] -> BoltActionT m [Graph NodeName (NodeRes PutRequest) (RelRes PutRequest)]

makeRequest :: (Requestable (NodeName, NodeReq PutRequest), Requestable ((NodeName, NodeName), RelReq PutRequest), Returnable (NodeName, NodeReq PutRequest), Returnable ((NodeName, NodeName), RelReq PutRequest), Extractable (NodeRes PutRequest), Extractable (RelRes PutRequest), MonadIO m) => [Text] -> Graph NodeName (NodeReq PutRequest) (RelReq PutRequest) -> BoltActionT m [Graph NodeName (NodeRes PutRequest) (RelRes PutRequest)]

type NodeReq PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type NodeReq PutRequest = PutNode

type RelReq PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type RelReq PutRequest = PutRelationship

type NodeRes PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type NodeRes PutRequest = BoltId

type RelRes PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

type RelRes PutRequest = BoltId

data PutNode

PutNode is the wrapper for Node where we can specify if we want to merge or create it.

Constructors

BoltId BoltId

Describe existing node by its BoltId. No new data will be inserted for this node.

MergeN Node

Merge the Node with existing node in the DB. Corresponds to MERGE Cypher operator.

CreateN Node

Create an entirely new node. Corresponds to CREATE Cypher operator.

Instances

Show PutNode

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

showsPrec :: Int -> PutNode -> ShowS

show :: PutNode -> String

showList :: [PutNode] -> ShowS

Returnable (NodeName, PutNode)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

isReturned' :: (NodeName, PutNode) -> Bool

return' :: (NodeName, PutNode) -> Text

Requestable (NodeName, PutNode)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

request :: (NodeName, PutNode) -> Text

data PutRelationship

PutRelationship is the wrapper for URelationship where we can specify if we want to merge or create it.

Meaning of constructors is the same as for PutNode.

Constructors

MergeR URelationship

CreateR URelationship

Instances

Show PutRelationship

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

showsPrec :: Int -> PutRelationship -> ShowS

show :: PutRelationship -> String

showList :: [PutRelationship] -> ShowS

Returnable ((NodeName, NodeName), PutRelationship)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

isReturned' :: ((NodeName, NodeName), PutRelationship) -> Bool

return' :: ((NodeName, NodeName), PutRelationship) -> Text

Requestable ((NodeName, NodeName), PutRelationship)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

request :: ((NodeName, NodeName), PutRelationship) -> Text

type GraphPutRequest = Graph NodeName PutNode PutRelationship

The graph of Nodes with specified uploading type and URelationships.

type GraphPutResponse = Graph NodeName BoltId BoltId

The graph of BoltIds corresponding to the nodes and relationships which we get after putting GraphPutRequest.

Internal machinery for forming Cypher queries

class GraphQuery a where

Type class used to perform requests to the Neo4j based on graphs.

Minimal complete definition

requestEntities

Associated Types

type NodeReq a :: *

Type of entity describing node for request.

type RelReq a :: *

Type of entity describing relationship for request.

type NodeRes a :: *

Type of node entity which will be extracted from result.

type RelRes a :: *

Type of relationship entity which will be extracted from result.

Methods

requestEntities :: (Requestable (NodeName, NodeReq a), Requestable ((NodeName, NodeName), RelReq a)) => [(NodeName, NodeReq a)] -> [((NodeName, NodeName), RelReq a)] -> (Text, [Text])

Convert requestable entities to text in the query.

formQuery

Arguments

:: (Requestable (NodeName, NodeReq a), Requestable ((NodeName, NodeName), RelReq a), Returnable (NodeName, NodeReq a), Returnable ((NodeName, NodeName), RelReq a))

=> [Text]

Custom conditions that will be added to WHERE block.

-> Graph NodeName (NodeReq a) (RelReq a)

Request graph template.

-> Text

Cypher query as text.

Abstract function to form query for request.

extractGraphs :: (Extractable (NodeRes a), Extractable (RelRes a), MonadIO m) => [NodeName] -> [(NodeName, NodeName)] -> [Record] -> BoltActionT m [Graph NodeName (NodeRes a) (RelRes a)]

Abstract function which exctracts graph from records if nodes and relations can be extracted.

makeRequest :: (Requestable (NodeName, NodeReq a), Requestable ((NodeName, NodeName), RelReq a), Returnable (NodeName, NodeReq a), Returnable ((NodeName, NodeName), RelReq a), Extractable (NodeRes a), Extractable (RelRes a), MonadIO m) => [Text] -> Graph NodeName (NodeReq a) (RelReq a) -> BoltActionT m [Graph NodeName (NodeRes a) (RelRes a)]

For given query graph, perform query and extract results graph.

Instances

GraphQuery PutRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

Associated Types

type NodeReq PutRequest :: Type

type RelReq PutRequest :: Type

type NodeRes PutRequest :: Type

type RelRes PutRequest :: Type

Methods

requestEntities :: [(NodeName, NodeReq PutRequest)] -> [((NodeName, NodeName), RelReq PutRequest)] -> (Text, [Text])

formQuery :: [Text] -> Graph NodeName (NodeReq PutRequest) (RelReq PutRequest) -> Text

extractGraphs :: (Extractable (NodeRes PutRequest), Extractable (RelRes PutRequest), MonadIO m) => [NodeName] -> [(NodeName, NodeName)] -> [Record] -> BoltActionT m [Graph NodeName (NodeRes PutRequest) (RelRes PutRequest)]

makeRequest :: (Requestable (NodeName, NodeReq PutRequest), Requestable ((NodeName, NodeName), RelReq PutRequest), Returnable (NodeName, NodeReq PutRequest), Returnable ((NodeName, NodeName), RelReq PutRequest), Extractable (NodeRes PutRequest), Extractable (RelRes PutRequest), MonadIO m) => [Text] -> Graph NodeName (NodeReq PutRequest) (RelReq PutRequest) -> BoltActionT m [Graph NodeName (NodeRes PutRequest) (RelRes PutRequest)]

GraphQuery GetRequest

Defined in Database.Bolt.Extras.Graph.Internal.GraphQuery

Associated Types

type NodeReq GetRequest :: Type

type RelReq GetRequest :: Type

type NodeRes GetRequest :: Type

type RelRes GetRequest :: Type

Methods

requestEntities :: [(NodeName, NodeReq GetRequest)] -> [((NodeName, NodeName), RelReq GetRequest)] -> (Text, [Text])

formQuery :: [Text] -> Graph NodeName (NodeReq GetRequest) (RelReq GetRequest) -> Text

extractGraphs :: (Extractable (NodeRes GetRequest), Extractable (RelRes GetRequest), MonadIO m) => [NodeName] -> [(NodeName, NodeName)] -> [Record] -> BoltActionT m [Graph NodeName (NodeRes GetRequest) (RelRes GetRequest)]

makeRequest :: (Requestable (NodeName, NodeReq GetRequest), Requestable ((NodeName, NodeName), RelReq GetRequest), Returnable (NodeName, NodeReq GetRequest), Returnable ((NodeName, NodeName), RelReq GetRequest), Extractable (NodeRes GetRequest), Extractable (RelRes GetRequest), MonadIO m) => [Text] -> Graph NodeName (NodeReq GetRequest) (RelReq GetRequest) -> BoltActionT m [Graph NodeName (NodeRes GetRequest) (RelRes GetRequest)]

class Requestable a where

Entity which can be requested from Neo4j in MATCH operator.

Methods

request :: a -> Text

How to convert entity to Cypher.

Instances

Requestable ((NodeName, NodeName), PutRelationship)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

request :: ((NodeName, NodeName), PutRelationship) -> Text

Requestable ((NodeName, NodeName), RelGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

request :: ((NodeName, NodeName), RelGetter) -> Text

Requestable (NodeName, PutNode)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

request :: (NodeName, PutNode) -> Text

Requestable (NodeName, NodeGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

request :: (NodeName, NodeGetter) -> Text

class Returnable a where

Entity which can be returned from Neo4j in RETURN operator.

Methods

isReturned' :: a -> Bool

If the entity should be returned.

return' :: a -> Text

How to return entity in the Cypher.

Instances

Returnable ((NodeName, NodeName), PutRelationship)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

isReturned' :: ((NodeName, NodeName), PutRelationship) -> Bool

return' :: ((NodeName, NodeName), PutRelationship) -> Text

Returnable ((NodeName, NodeName), RelGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

isReturned' :: ((NodeName, NodeName), RelGetter) -> Bool

return' :: ((NodeName, NodeName), RelGetter) -> Text

Returnable (NodeName, PutNode)

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

isReturned' :: (NodeName, PutNode) -> Bool

return' :: (NodeName, PutNode) -> Text

Returnable (NodeName, NodeGetter)

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

isReturned' :: (NodeName, NodeGetter) -> Bool

return' :: (NodeName, NodeGetter) -> Text

class Extractable a where

Entity which can be extracted from Record by its name.

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [a]

Instances

Extractable BoltId

Defined in Database.Bolt.Extras.Graph.Internal.Put

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [BoltId]

Extractable RelResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [RelResult]

Extractable NodeResult

Defined in Database.Bolt.Extras.Graph.Internal.Get

Methods

extract :: MonadIO m => Text -> [Record] -> BoltActionT m [NodeResult]

type NodeName = Text

Alias for text node name.

relationName :: (NodeName, NodeName) -> Text

Build relationship name from the names of its start and end nodes like [startNodeName]0[endNodeName].

requestGetters :: [(NodeName, NodeGetter)] -> [((NodeName, NodeName), RelGetter)] -> (Text, [Text])

Takes all node getters and relationship getters and write them to single query to request. Also return conditions on known boltId-s.

requestPut :: [(NodeName, PutNode)] -> [((NodeName, NodeName), PutRelationship)] -> (Text, [Text])

Takes all PutNodes and PutRelationships and write them to single query to request. Here WITH is used, because you cannot perform "match", "merge" or "create" at the same query.

(#) :: a -> (a -> b) -> b

A synonym for &. Kept for historical reasons.