org.neo4j.driver.v1

Interface StatementResult

All Superinterfaces:

Iterator<Record>

public interface StatementResult
extends Iterator<Record>

The result of running a Cypher statement, conceptually a stream of records. The standard way of navigating through the result returned by the database is to iterate over it. Results are valid until the next statement is run or until the end of the current transaction, whichever comes first. To keep a result around while further statements are run, or to use a result outside the scope of the current transaction, see list().

Important note on semantics

In order to handle very large results, and to minimize memory overhead and maximize performance, results are retrieved lazily. Please see StatementRunner for important details on the effects of this. The short version is that, if you want a hard guarantee that the underlying statement has completed, you need to either call Resource.close() on the Transaction or Session that created this result, or you need to use the result. Calling any method on this interface will guarantee that any write operation has completed on the remote database.

Since:

1.0

Method Summary

Modifier and Type	Method and Description
ResultSummary	consume() Consume the entire result, yielding a summary of it.
boolean	hasNext() Test if there is another record we can navigate to in this result.
List<String>	keys() Retrieve the keys of the records this result contains.
List<Record>	list() Retrieve and store the entire result stream.
<T> List<T>	list(Function<Record,T> mapFunction) Retrieve and store a projection of the entire result.
Record	next() Navigate to and retrieve the next Record in this result.
Record	peek() Investigate the next upcoming record without moving forward in the result.
Record	single() Return the first record in the result, failing if there is not exactly one record left in the stream Calling this method always exhausts the result, even when NoSuchRecordException is thrown.
ResultSummary	summary() Return the result summary.

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Method Detail

keys

List<String> keys()

Retrieve the keys of the records this result contains.

Returns:

all keys

hasNext

boolean hasNext()

Test if there is another record we can navigate to in this result.

Specified by:

hasNext in interface Iterator<Record>

Returns:

true if next() will return another record

next

Record next()

Navigate to and retrieve the next Record in this result.

Specified by:

next in interface Iterator<Record>

Returns:

the next record

Throws:

NoSuchRecordException - if there is no record left in the stream

single

Record single()
       throws NoSuchRecordException

Return the first record in the result, failing if there is not exactly one record left in the stream Calling this method always exhausts the result, even when NoSuchRecordException is thrown.

Returns:

the first and only record in the stream

Throws:

NoSuchRecordException - if there is not exactly one record left in the stream

peek

Record peek()

Investigate the next upcoming record without moving forward in the result.

Returns:

the next record

Throws:

NoSuchRecordException - if there is no record left in the stream

list

List<Record> list()

Retrieve and store the entire result stream. This can be used if you want to iterate over the stream multiple times or to store the whole result for later use. Note that this method can only be used if you know that the statement that yielded this result returns a finite stream. Some statements can yield infinite results, in which case calling this method will lead to running out of memory. Calling this method exhausts the result.

Returns:

list of all remaining immutable records

list

<T> List<T> list(Function<Record,T> mapFunction)

Retrieve and store a projection of the entire result. This can be used if you want to iterate over the stream multiple times or to store the whole result for later use. Note that this method can only be used if you know that the statement that yielded this result returns a finite stream. Some statements can yield infinite results, in which case calling this method will lead to running out of memory. Calling this method exhausts the result.

Type Parameters:

T - the type of result list elements

Parameters:

mapFunction - a function to map from Record to T. See Records for some predefined functions.

Returns:

list of all mapped remaining immutable records

consume

ResultSummary consume()

Consume the entire result, yielding a summary of it. Calling this method exhausts the result.

 ResultSummary summary = session.run( "PROFILE MATCH (n:User {id: 12345}) RETURN n" ).consume();
 
 

Returns:

a summary for the whole query result

summary

ResultSummary summary()

Return the result summary. If the records in the result is not fully consumed, then calling this method will force to pull all remaining records into buffer to yield the summary. If you want to obtain the summary but discard the records, use consume() instead.

Returns:

a summary for the whole query result.