Neo4j server plugin basic questions -

Neo4j server plugin basic questions -

i using neo4j v2.1.5 , creating server plugin.

how create unique node i.e. guarantee uniqueness of property? is there hook in plugin lifecycle, constraints , indexes can created? returning node returns finish database. how can homecoming node or pojo list json? there working examples or explanation of representation available?

i using java api , not cypher.

how create unique node i.e. guarantee uniqueness of property?

you can create unique constraint on (label, property) pair ensure uniqueness of property.

e.g.

create unique constraint on :person(name)

would ensure can't have 2 people nodes same name. if want java api you'd like this:

try ( transaction tx = graphdb.begintx() ) { graphdb.schema() .constraintfor( dynamiclabel.label( "person" ) ) .assertpropertyisunique( "name" ) .create(); tx.success(); }

is there hook in plugin lifecycle, constraints , indexes can created?

you can in transaction iirc can create 1 index/constraint per transaction.

returning node returns finish database. how can homecoming node or pojo list? there working examples or explanation of representation available?

do mean cypher? simple query homecoming 1 node this:

match (n) homecoming n limit 1

in cypher land homecoming map of properties node has on it. if want more specific seek this:

match (n:person) homecoming n.name personname limit 1

so you'd string column in result set.

-- updating java api --

from java api can write own traversals give 'node' , 'relationship' objects. you'd have extract properties you're interested in.

try ( transaction tx = graphdatabaseservice.begintx() ) { resourceiterable<node> people = globalgraphoperations.at( graphdatabaseservice ).getallnodeswithlabel( dynamiclabel.label( "person" ) ); ( node node : people ) { string name = (string) node.getproperty( "name" ); } tx.success(); }

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