Naming rules and recommendations

This page describes rules and recommendations for the naming of node labels, relationship types, property names, variables, indexes, and constraints.

Naming rules

  • Alphabetic characters:

    • Names should begin with an alphabetic character.

    • This includes "non-English" characters, such as å, ä, ö, ü etc.

  • Numbers:

    • Names should not begin with a number.

    • To illustrate, 1first is not allowed, whereas first1 is allowed.

  • Symbols:

    • Names should not contain symbols, except for underscore, as in my_variable, or $ as the first character to denote a parameter, as given by $myParam.

  • Length:

    • Can be very long, up to 65535 (2^16 - 1) or 65534 characters, depending on the version of Neo4j.

  • Case-sensitive:

    • Names are case-sensitive and thus, :PERSON, :Person and :person are three different labels, and n and N are two different variables.

  • Whitespace characters:

    • Leading and trailing whitespace characters will be removed automatically. For example, MATCH ( a ) RETURN a is equivalent to MATCH (a) RETURN a.

Using special characters in names

Non-alphabetic characters, including numbers, symbols and whitespace characters, can be used in names, but must be escaped using backticks. For example: `^n`, `1first`, `$$n`, and `my variable has spaces`. Database names are an exception and may include dots without the need for escaping. For example: naming a database foo.bar.baz is perfectly valid.

Within an escaped name, the following escaping sequences are allowed:

Escape sequence Character

``

Backtick

\uxxxx

Unicode UTF-16 code point (4 hex digits must follow the \u)

Using escaped names with unsanitized user input makes you vulnerable to Cypher® injection. Some techniques to mitigate this are:

  • sanitizing (and validating) the user input.

  • remodeling your data model to avoid this data access pattern.

Several special characters have been deprecated and will require escaping in the next major release of Neo4j. For the comprehensive list of deprecated characters, see the deprecations page.

Scoping and namespace rules

  • Node labels, relationship types and property names may re-use names.

    • The following query — with a for the label, type and property name — is valid: CREATE (a:a {a: 'a'})-[r:a]->(b:a {a: 'a'}).

  • Variables for nodes and relationships must not re-use names within the same query scope.

    • The following query is not valid as the node and relationship both have the name a: CREATE (a)-[a]->(b).

Recommendations

Here are the recommended naming conventions:

Node labels

Camel-case, beginning with an upper-case character

:VehicleOwner rather than :vehicle_owner etc.

Relationship types

Upper-case, using underscore to separate words

:OWNS_VEHICLE rather than :ownsVehicle etc.

Length limit of identifiers

Neo4j’s block format implements GQL’s limit on the maximum length of identifiers.

The maximum limit is set to 16,383 characters in an identifier. This means that node labels, relationship types, and property keys cannot include more than 16,383 characters.