Cypher supports querying with parameters. This allows developers to not to have to do string building to create a query, and it also makes caching of execution plans much easier for Cypher.
Parameters can be used for literals in the WHERE
clause, for the index key and index value in the START
clause, index queries, and finally for node/relationship ids.
Accepted names for parameter are letters and number, and any combination of these.
Here follows a few examples of how you can use parameters from Java.
Parameter for node id
Map<String, Object> params = new HashMap<String, Object>(); params.put( "id", 0 ); ExecutionResult result = engine.execute( "start n=node({id}) return n.name", params );
Parameter for node object
Map<String, Object> params = new HashMap<String, Object>(); params.put( "node", andreasNode ); ExecutionResult result = engine.execute( "start n=node({node}) return n.name", params );
Parameter for multiple node ids
Map<String, Object> params = new HashMap<String, Object>(); params.put( "id", Arrays.asList( 0, 1, 2 ) ); ExecutionResult result = engine.execute( "start n=node({id}) return n.name", params );
Parameter for string literal
Map<String, Object> params = new HashMap<String, Object>(); params.put( "name", "Johan" ); ExecutionResult result = engine.execute( "start n=node(0,1,2) where n.name = {name} return n", params );
Parameter for index key and value
Map<String, Object> params = new HashMap<String, Object>(); params.put( "key", "name" ); params.put( "value", "Michaela" ); ExecutionResult result = engine.execute( "start n=node:people({key} = {value}) return n", params );
Parameter for index query
Map<String, Object> params = new HashMap<String, Object>(); params.put( "query", "name:Andreas" ); ExecutionResult result = engine.execute( "start n=node:people({query}) return n", params );
Map<String, Object> params = new HashMap<String, Object>(); params.put( "s", 1 ); params.put( "l", 1 ); ExecutionResult result = engine.execute( "start n=node(0,1,2) return n.name skip {s} limit {l}", params );
Map<String, Object> params = new HashMap<String, Object>(); params.put( "regex", ".*h.*" ); ExecutionResult result = engine.execute( "start n=node(0,1,2) where n.name =~ {regex} return n.name", params );
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