How do I define, display, and use parameters with neo4j-shell

parameters
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(Dana Canzano) #1

bin/neo4j-shell allows for a command line interface to query your graph via Cypher statements and to include parameters to those statements.
Usage of parameters, rather than hard coding values, will allow for re-use of the query plan cache.

A parameter can be defined within neo4j-shell via the export command, for example:

neo4j-sh (?)$ export p1="Nora Ephron"

Multi-word values for parameters should be enclosed in double quotes. +
Parameters can be displayed within neo4j-shell via the env command, for example:

neo4j-sh (?) export p1="Nora Ephron" neo4j-sh (?) env
TITLE_MAX_LENGTH=40
p1=Nora Ephron
TITLE_KEYS=.name.,.title.

Once a parameter is defined, it can be used in a Cypher statement, for example:

neo4j-sh (?) export p1="Nora Ephron" neo4j-sh (?) env
TITLE_MAX_LENGTH=40
p1=Nora Ephron
TITLE_KEYS=.name.,.title.
neo4j-sh (?)$ match (n:Person {name:'Tom Hanks'})-[:ACTED_IN]->(n1:Movie)<-[:DIRECTED]-(n2:Person {name:{p1}}) return n1.title;

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