The Neo4j Manual v3.1.0-SNAPSHOT30.6. How to use (individual commands)

Single line comments, which will be ignored, can be made by using the prefix //. Example:

// This is a comment

You have a current node/relationship and a "current path" (like a current working directory in bash) that you’ve traversed so far. When the shell first starts you are not positioned on any entity, but you can cd your way through the graph (check your current path at any time with the pwd command). cd can be used in different ways:

List contents of the current node/relationship (or any other node) with the ls command. Please note that it will give an empty output if the current node/relationship has no properties or relationships (for example in the case of a brand new graph). ls can take a node id as argument as well as filters, see Section 30.4, “Filters” and for information about how to specify direction see Section 30.3, “Enum options”. Use man ls for more info.

You create new nodes by connecting them with relationships to the current node. For example, mkrel -t A_RELATIONSHIP_TYPE -d OUTGOING -c will create a new node (-c) and draw to it an OUTGOING relationship of type A_RELATIONSHIP_TYPE from the current node. If you already have two nodes which you’d like to draw a relationship between (without creating a new node) you can do for example, mkrel -t A_RELATIONSHIP_TYPE -d OUTGOING -n <other-node-id> and it will just create a new relationship between the current node and that other node.

Property operations are done with the set, mv and rm commands. These commands operates on the current node/relationship.

Use set <key> <value>, optionally with the -t option (for value type), to set a property. Supports every type of value that Neo4j supports. Examples of a property of type int:

$ set -t int age 29

And an example of setting a double[] property:

$ set -t double[] my_values [1.4,12.2,13]

Example of setting a String property containing a JSON string:

mkrel -c -d i -t DOMAIN_OF --np "{'app':'foobar'}"

Deletion of nodes and relationships is done with the rmnode and rmrel commands. rmnode can delete nodes, if the node to be deleted still has relationships they can also be deleted by supplying -f option. rmrel can delete relationships, it tries to ensure connectedness in the graph, but relationships can be deleted regardless with the -f option. rmrel can also delete the node on the other side of the deleted relationship if it’s left with no more relationships, see -d option.

The shell uses environment variables a-la bash to keep session information, such as the current path and more. The commands for this mimics the bash commands export and env. For example you can at anytime issue a export STACKTRACES=true command to set the STACKTRACES environment variable to true. This will then result in stacktraces being printed if an exception or error should occur. Allowed values are all parseable JSON strings, so maps {age:10,name:"Mattias"} and arrays [1,2,3] are also supported.

Variables can also be assigned to each other. E.g. a=b will result in a containing the value of b.

This becomes especially interesting as all shell variables are automatically passed to cypher statements as parameters. That makes it easy to query for certain start nodes or create nodes and relationships with certain provided properties (as maps).

Values are removed by setting them to null or an empty value. List environment variables using env

The shell has support for executing scripts, such as Groovy and Python (via Jython). As of now the scripts (*.groovy, *.py) must exist on the server side and gets called from a client with for example, gsh --renamePerson 1234 "Mathias" "Mattias" --doSomethingElse where the scripts renamePerson.groovy and doSomethingElse.groovy must exist on the server side in any of the paths given by the GSH_PATH environment variable (defaults to .:src:src/script). This variable is like the java classpath, separated by a :. The python/jython scripts can be executed with the jsh in a similar fashion, however the scripts have the .py extension and the environment variable for the paths is JSH_PATH.

When writing the scripts assume that there’s made available an args variable (a String[]) which contains the supplied arguments. In the case of the renamePerson example above the array would contain ["1234", "Mathias", "Mattias"]. Also please write your outputs to the out variable, such as out.println( "My tracing text" ) so that it will be printed at the shell client instead of the server.

You can traverse the graph with the trav command which allows for simple traversing from the current node. You can supply which relationship types (w/ regex matching) and optionally direction as well as property filters for matching nodes. In addition to that you can supply a command line to execute for each match. An example: trav -o depth -r KNOWS:both,HAS_.*:incoming -c "ls $n". Which means traverse depth first for relationships with type KNOWS disregarding direction and incoming relationships with type matching HAS_.\* and do a ls <matching node> for each match. The node filtering is supplied with the -f option, see Section 30.4, “Filters”. See Section 30.3, “Enum options” for the traversal order option. Even relationship types/directions are supplied using the same format as filters.

You can use Cypher to query the graph. For that, use the match or start command. You can also use create statements to create nodes and relationships and use the cypher VERSION prefix to select a certain cypher version.

Tip Cypher queries need to be terminated by a semicolon ;.

Cypher commands are given all shell variables as parameters and the special self parameter for the current node or relationship.

The schema command provides information about indexes and constraints together with their current status.

Note This command does not list legacy indexes. For working with legacy indexes, please see the section called “Legacy Indexing”.

The schema command supports the following actions:

The schema command also supports the following optional parameters:

schema ls -l :Person

schema ls -r :KNOWS

schema progress -l :Person -p name

schema ls -v

schema sample -a

schema sample -f -l :Person :p name

Indexes and constraints can be created or removed using Cypher or the Java Core API. They are updated automatically whenever the graph is changed. See the section called “Schema” for more information.

It’s possible to query and manipulate legacy indexes via the index command.

Example: index -i persons name (will index the name for the current node or relationship in the "persons" legacy index).

It is useful to be able to test changes, and then being able to commit or rollback said changes.

Transactions can be nested. With a nested transaction, a commit does not write any changes to disk, except for the top level transaction. A rollback, however works regardless of the level of the transaction. It will roll back all open transactions.

Experimental feature The dump command has incomplete functionality. It might not work for your use case or data size.

As a simple way of exporting a database or a subset of it, the dump command converts the graph of a Cypher result or the whole database into a single Cypher create statement.

Examples:

 # create a new node and go to it
 neo4j-sh (?)$ mknode --cd --np "{'name':'Neo'}"

 # create a relationship
 neo4j-sh (Neo,0)$ mkrel -c -d i -t LIKES --np "{'app':'foobar'}"

 # Export the cypher statement results
 neo4j-sh (Neo,0)$ dump MATCH (n)-[r]-(m) WHERE n = {self} return n,r,m;
 begin
 commit
 begin
 create (_0 {`name`:"Neo"})
 create (_1 {`app`:"foobar"})
 create (_1)-[:`LIKES`]->(_0)
 ;
 commit