Querying with mgconsole

The easiest way to execute Cypher queries against Memgraph is by using Memgraph's command-line tool, mgconsole.

1. Install mgconsole

tip

If you installed Memgraph Platform with the Docker image (memgraph/memgraph-platform), mgconsole will start automatically when you run the container. Skip the installation steps and continue with executing Cypher queries.

If you installed any other Docker image or want to explicitly start the mgconsole from the Memgraph Platform image, you need to manually run mgconsole following the steps described below.

If you want to install or run mgconsole to query a running Memgraph database instance, use the following steps:

Docker 🐳

If you installed MemgraphDB using Docker or closed the terminal with the running mgconsole from Memgraph Platform image, run the mgconsole client from your Docker image using the following commands:

1. First, you need to find the CONTAINER_ID by running:

docker ps

2. Once you know the CONTAINER_ID, you can start mgconsole by running the following command:

docker exec -it CONTAINER_ID mgconsole

Windows

1. Download mgconsole from the Download Hub.

2. From PowerShell, start mgconsole with the command:

./mgconsole --host HOST --port PORT

If Memgraph is running locally using the default configuration, start mgconsole with:

./mgconsole --host 127.0.0.1 --port 7687

macOS

1. Download mgconsole from the Download Hub.

2. From the terminal, provide execution permission to the current user:

chmod u+x ./mgconsole

3. Start mgconsole with the command:

./mgconsole --host HOST --port PORT

If Memgraph is running locally using the default configuration, start mgconsole with:

./mgconsole --host 127.0.0.1 --port 7687

Linux

note

We will soon release a downloadable Debian package, so you don't have to install mgconsole from source.

1. Follow the instructions on how to build and install mgconsole from source.

2. Start mgconsole with the command:

mgconsole --host HOST --port PORT

If Memgraph is running locally using the default configuration, start mgconsole with:

mgconsole --host 127.0.0.1 --port 7687

2. Execute a Cypher query

After the client has started, it should present a command prompt similar to:

mgconsole X.X
Connected to 'memgraph://127.0.0.1:7687'
Type :help for shell usage
Quit the shell by typing Ctrl-D(eof) or :quit
memgraph>

At this point, it is possible to execute Cypher queries against a running Memgraph database instance.

tip

You can use the TAB key to autocomplete commands in mgconsole.

Each query needs to end with the ; (semicolon) character. For example:

CREATE (u:User {name: "Alice"})-[:Likes]->(m:Software {name: "Memgraph"});

The above query will create 2 nodes in the database, one labeled "User" with name "Alice" and the other labeled "Software" with name "Memgraph". It will also create a relationship that "Alice" likes "Memgraph".

To find created nodes and relationships, execute the following query:

MATCH (u:User)-[r]->(x) RETURN u, r, x;

Query execution time

To get a breakdown of the execution time, set the -verbose_execution_info flag to true.

Upon query execution you will get this information:

Query COST estimate: 3066
Query PARSING time: 0.000175982 sec
Query PLAN EXECUTION time: 0.0154524 sec
Query PLANNING time: 8.054e-05 sec

The values show:

• COST estimate - Internal planner estimation on the cost of the query. When comparing two query executions, an order of magnitude larger COST estimates might indicate the query's longer execution time.
• PARSING time - Time spent checking if the query is valid and normalizing it for cache.
• PLAN EXECUTION time - Time executing the plan.
• PLANNING time - Time it takes the query planner to create the optimal plan to execute the query.

Configure mgconsole

Below are configurational flags you can use with mgconsole:

Main

Flag	Description	Type	Default
-csv_delimiter	Character used to separate fields.	string	","
-csv_doublequote	Controls how instances of the quotechar(") appearing inside a field should themselves be quoted. When true, the character is doubled. When false, the escapechar is used as a prefix to the quotechar. If csv_doublequote is false, csv_escapechar must be set.	bool	true
-csv_escapechar	Character used to escape the quote character (") if csv_doublequote is false.	string	""
-fit_to_screen	Fit output width to screen width.	bool	false
-history	Use the specified directory to save history.	string	"~/.memgraph"
-host	Server address. It can be a DNS resolvable hostname.	string	"127.0.0.1"
-no_history	Do not save history.	bool	false
-output_format	Query output format. Can be csv or tabular. If the output format is not tabular fit_to_screen flag is ignored.	string	"tabular"
-password	Database password.	string	""
-port	Server port.	int32	7687
-term_colors	Use terminal colors syntax highlighting.	bool	false
-use_ssl	Use SSL when connecting to the server.	bool	false
-username	Database username.	string	""
-verbose_execution_info	Output the additional information about query such as query cost, parsing, planning and execution times.	bool	false

Flags

Flag	Description	Type	Default
-flagfile	Load flags from a file.	string	""
-fromenv	Set flags from the environment [example: 'export FLAGS_flag1=value'].	string	""
-tryfromenv	Set flags from the environment if present.	string	""
-undefok	Comma-separated list of flag names. These flags can be specified on the command line even if the program does not define a flag with that name. IMPORTANT: Flags from the list that have arguments MUST use the flag=value format.	string	""
-tab_completion_columns	The number of columns used in output for tab completion.	int32	80
-tab_completion_word	If non-empty, HandleCommandLineCompletions() will hijack the process and attempt to do bash-style command line flag completion on this value.	string	""

Help

Flag	Description	Type	Default
-help	Show help on all flags [tip: all flags can have two dashes].	bool	false
-helpfull	Show help on all flags -- same as -help.	bool	false
-helpmatch	Show help on modules, names of which contain the specified substring.	string	""
-helpon	Show help on the modules named by this flag value.	string	""
-helppackage	Show help on all modules in the main package.	bool	false
-helpshort	Show help on the main module for this program only.	bool	false
-helpxml	Produce an .xml version of help.	bool	false
-version	Show version and build info then exit.	bool	false

caution

When working with Memgraph Platform, you should pass configuration flags inside of environment variables.

For example, you should start Memgraph Platform with docker run -e MGCONSOLE="-output_format="csv"" memgraph/memgraph-platform.

Non-interactive mode

To get the query result in bash, use the following command:

mgconsole < <(echo "MATCH (n:Person) RETURN n;")

or

echo "MATCH (n:Person) RETURN n;" | mgconsole

To save the query results in a file, use the following command:

mgconsole < <(echo "MATCH (n:Person) RETURN n;") > results.txt

Where to next?

If you want to learn more about graph databases and Cypher queries, visit Memgraph Playground and go through the guided lessons. All the datasets and most of the queries used in the guided lessons can also be explored in the Tutorials section, and knowledge about Cypher is gathered in the Cypher manual.

If you are all good to go on your own - import your data!