Schema Classes

class GraphObject(graph=None, **properties)

The base class for Node and Relationship

Parameters:
  • graph (Graph) – The graph instance to which the object should write.
  • var (str) – The Cypher variable representing the object.
  • properties (Property) – The Property objects associated with the Node. String arguments are automatically converted into Property objects of the default string type.
bind(*keys)
Parameters:keys (str) – The names of properties to bind to. If none are provided, the default is to bind to all Properties marked as primary keys, if any.
bound_keys

A tuple representing the keys to which the object is currently bound.

is_bound

A boolean indicating whether or not the object is bound. This can be True even if bound_keys is empty.

properties

A dict representing properties and their current values. Note that editing this dict does not set properties!

items()

A dict-like method providing a tuple of pairs of property names and Property objects.

keys()

A dict-like method providing a tuple of names of attributes which correspond to Properties.

values()

A dict-like method providing a tuple of Property objects defined for the object.

class Node(*labels, **properties)

The core of the low-level QueryBuilder API. Represents a Node in Neo4J along with its labels and properties.

Parameters:
  • labels (str) – The labels for the Node. These should be defined from least to most specific.
  • var (str) – The Cypher variable representing the node.
  • properties (Property) – The Property objects associated with the Node. String arguments are automatically converted into Property objects of the default string type.
type

The primary label that defines the Node.

labels

The set of all labels shared by the Node’s members.

class Relationship(type, start_node=None, end_node=None, depth=None, directed=True, var='rel', **properties)
Parameters:
  • type (str) – The relationship’s type, which in NeoAlchemy is required.
  • start_node (Node) – The node represented by a, in (a)-[:TYPE]->(b).
  • end_node (Node) – The node represented by b, in (a)-[:TYPE]->(b).
  • depth – A variable property to control the depth of the relationship when used as part of a Cypher statement. -1 indicates “infinite” depth (*), any positive integer n represents that depth (*n), and any tuple of positive integers (m, n) represents a range (*m..n).
  • directed (bool) – Whether or not the relation is directed. Default is True (directed relation). Note that some operations (such as merge) become effectively arbitrary on undirected relationships. This is a limitation of Neo4J.
  • var (str) – The Cypher variable representing the relationship.
  • properties (Property) – The Property objects associated with the Node. String arguments are automatically converted into Property objects of the default string type.
exists(exists=True)

Returns a CypherExpression corresponding to the EXISTS function in Cypher.

Parameters:exists (bool) – If False, do NOT EXISTS instead. Default is True.
class Property(obj=None, type=str, default=None, value=None, indexed=False, unique=False, required=False, primary_key=False, read_only=False)

Represents an optionally constrained property on a GraphObject.

Parameters:
  • obj (GraphObject) – The object to which the Property will be bound.
  • type (callable) – Any callable used to convert a property value’s type. Typically a built-in Python type or something found in the neoalchemy.validators module.
  • default – The default value for the property if not specified. This can be a callable. Either the value (or the return value if callable) must pass validation given by type.
  • value – The starting value for the property. Must pass validation given by type.
  • indexed (bool) – If set, create an index for the property.
  • unique (bool) – If set, create a unique constraint for the property. This implies indexed=True.
  • required (bool) – If set, create a property existence constraint for the property. Only available with Neo4J Enterprise.
  • primary_key (bool) – If set, the property is one of the object’s default bindings when :py:method::~neoalchemy.GraphObject.bind is called with no arguments.
  • read_only (bool) – Not yet implemented.
value

The current value of the property.

var

The current Cypher variable for the property. A property must be bound to a GraphObject to compute its Cypher variable.

class Graph
delete_all()

Issues MATCH (all) DETACH DELETE all, completely clearing the graph.

It should go without saying that this will delete all of your data!

query(query, **params)

Run an arbitrary query against the graph, with optional parameters.

When not called, returns a reference to the Graph’s graph.query object.

Parameters:
  • query – An object that stringifies to a Cypher query.
  • params – The values for the query’s parameters.
Returns:

A Neo4J StatementResult corresponding to the issued query.
Return type:

neo4j.v1.StatementResult
schema

A reference to the Graph’s graph.schema object.

session()

Returns a session from the underlying driver’s pool.

class graph.query
all()

Returns the result of MATCH (all) RETURN all.

log(query, params)

Log the given query and parameters. For other options, see graph.query.log.

class graph.query.log
MAX_SIZE

int The maximum number of log entries to store.

class graph.schema
create(node)

Create the schema for the Node.

Parameters:node (Node) – The Node instance to add to the schema
Return type:None
drop(node)

Drop the schema for the Node.

Parameters:node (Node) – The Node instance to drop from the schema
Return type:None
constraints

Get current graph constraints lazily.

On first access, this fetches from the database. Afterwards, call update() to refresh.

indexes

Get current graph indexes lazily.

On first access, this fetches from the database. Afterwards, call update() to refresh.

labels

Get current graph labels lazily.

On first access, this fetches from the database. Afterwards, call update() to refresh.

ls

Cypher statements for currently defined schema.

update()

Refresh constraints, indexes, and labels.