com.datastax.driver.dse.graph

Class GraphStatement

java.lang.Object

com.datastax.driver.dse.graph.GraphStatement

Direct Known Subclasses:

RegularGraphStatement

public abstract class GraphStatement
extends Object

An executable graph query.

Constructor Summary

Constructors

Constructor and Description
GraphStatement()

Method Summary

Modifier and Type	Method and Description
GraphStatement	executingAs(String userOrRole) Allows this statement to be executed as a different user/role than the one currently authenticated (a.k.a.
abstract ConsistencyLevel	getConsistencyLevel() Returns the consistency level to use with this statement.
abstract long	getDefaultTimestamp() The default timestamp for this query.
String	getGraphInternalOption(String optionKey) Returns the advanced option's value defined for the key in parameter.
String	getGraphLanguage() Returns the graph language to use with this statement.
String	getGraphName() Returns the graph name to use with this statement.
ConsistencyLevel	getGraphReadConsistencyLevel() Returns the read consistency level to use with this statement.
String	getGraphSource() Returns the graph traversal source name to use with this statement.
ConsistencyLevel	getGraphWriteConsistencyLevel() Returns the write consistency level to use with this statement.
abstract int	getReadTimeoutMillis() Return the per-host socket read timeout that was set for this statement.
Function<Row,GraphNode>	getTransformResultFunction() Allows users to input their own implementations of GraphNode directly into the DSE Driver's workflow.
Boolean	isIdempotent() Whether this statement is idempotent, i.e.
boolean	isSystemQuery() Returns whether this statement is marked as a system query.
abstract GraphStatement	setConsistencyLevel(ConsistencyLevel consistencyLevel) Sets the consistency level to use for this statement.
abstract GraphStatement	setDefaultTimestamp(long defaultTimestamp) Sets the default timestamp for this query (in microseconds since the epoch).
GraphStatement	setGraphInternalOption(String optionKey, String optionValue) Sets additional graph option.
GraphStatement	setGraphLanguage(String graphLanguage) Sets the graph language to use with this statement.
GraphStatement	setGraphName(String graphName) Sets the graph name to use with this statement.
GraphStatement	setGraphReadConsistencyLevel(ConsistencyLevel consistencyLevel) Sets the read consistency level to use for this statement.
GraphStatement	setGraphSource(String graphSource) Sets the graph traversal source name to use with this statement.
GraphStatement	setGraphWriteConsistencyLevel(ConsistencyLevel consistencyLevel) Sets the write consistency level to use for this statement.
GraphStatement	setIdempotent(boolean idempotent) Sets whether this statement is idempotent.
abstract GraphStatement	setReadTimeoutMillis(int readTimeoutMillis) Overrides the default per-host read timeout (GraphOptions.setReadTimeoutMillis(int)) for this statement.
GraphStatement	setSystemQuery() Forces this statement to use no graph name, even if a default graph name was defined with GraphOptions.setGraphName(String).
GraphStatement	setTransformResultFunction(Function<Row,GraphNode> transformResultFunction) Sets the function to transform a Row to a GraphNode.
abstract Statement	unwrap() "Unwraps" the current graph statement, that is, returns an executable Statement object corresponding to this graph statement.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GraphStatement

public GraphStatement()

Method Detail

getGraphLanguage

public String getGraphLanguage()

Returns the graph language to use with this statement.

Returns:

the graph language to use with this statement.

See Also:

setGraphLanguage(String)

setGraphLanguage

public GraphStatement setGraphLanguage(String graphLanguage)

Sets the graph language to use with this statement.

This property is not required; if it is not set, the default GraphOptions.getGraphLanguage() will be used when executing the statement.

Parameters:

graphLanguage - the Graph language to use with this statement.

Returns:

this GraphStatement instance (for method chaining).

getGraphSource

public String getGraphSource()

Returns the graph traversal source name to use with this statement.

Returns:

the graph traversal source name to use with this statement.

See Also:

setGraphSource(String)

setGraphSource

public GraphStatement setGraphSource(String graphSource)

Sets the graph traversal source name to use with this statement.

This property is not required; if it is not set, the default GraphOptions.getGraphSource() will be used when executing the statement.

Parameters:

graphSource - the graph traversal source name to use with this statement.

Returns:

this GraphStatement instance (for method chaining).

getGraphName

public String getGraphName()

Returns the graph name to use with this statement.

Returns:

the graph name to use with this statement.

See Also:

getGraphName()

setGraphName

public GraphStatement setGraphName(String graphName)

Sets the graph name to use with this statement.

This property is not required; if it is not set, the default GraphOptions.getGraphName() (which may itself be unset) will be used when executing the statement.

If a default name is set on the global options, but this statement is a system query that you explicitly want to run without a graph name, use setSystemQuery().

If setSystemQuery() was called on this statement previously, setting a graph name forces the statement to be a non-system query again.

Parameters:

graphName - the graph name to use with this statement.

Returns:

this GraphStatement instance (for method chaining).

setSystemQuery

public GraphStatement setSystemQuery()

Forces this statement to use no graph name, even if a default graph name was defined with GraphOptions.setGraphName(String).

If a graph name was previously defined on this statement, it will be reset.

Returns:

this GraphStatement instance (for method chaining).

isSystemQuery

public boolean isSystemQuery()

Returns whether this statement is marked as a system query.

Returns:

whether this statement is marked as a system query.

getGraphReadConsistencyLevel

public ConsistencyLevel getGraphReadConsistencyLevel()

Returns the read consistency level to use with this statement.

Returns:

the read consistency level configured with this statement.

setGraphReadConsistencyLevel

public GraphStatement setGraphReadConsistencyLevel(ConsistencyLevel consistencyLevel)

Sets the read consistency level to use for this statement.

This setting will override the consistency level set with setConsistencyLevel(ConsistencyLevel) only for the READ part of the graph query.

Please see setConsistencyLevel(ConsistencyLevel) for more information.

Parameters:

consistencyLevel - the consistency level to set.

Returns:

this GraphStatement instance (for method chaining).

setIdempotent

public GraphStatement setIdempotent(boolean idempotent)

Sets whether this statement is idempotent.

Parameters:

idempotent - the new value.

Returns:

this Statement object.

See Also:

Statement.isIdempotent()

isIdempotent

public Boolean isIdempotent()

Whether this statement is idempotent, i.e. whether it can be applied multiple times without changing the result beyond the initial application.

Returns:

whether this statement is idempotent, or null if it uses the default QueryOptions.getDefaultIdempotence().

See Also:

Statement.setIdempotent(boolean)

getGraphWriteConsistencyLevel

public ConsistencyLevel getGraphWriteConsistencyLevel()

Returns the write consistency level to use with this statement.

Returns:

the write consistency level configured with this statement.

setGraphWriteConsistencyLevel

public GraphStatement setGraphWriteConsistencyLevel(ConsistencyLevel consistencyLevel)

Sets the write consistency level to use for this statement.

This setting will override the consistency level set with setConsistencyLevel(ConsistencyLevel) only for the write part of the graph query.

Please see setConsistencyLevel(ConsistencyLevel) for more information.

Parameters:

consistencyLevel - the consistency level to set.

Returns:

this GraphStatement instance (for method chaining).

setGraphInternalOption

public GraphStatement setGraphInternalOption(String optionKey,
                                             String optionValue)

Sets additional graph option. Those options are supposed to be used by advanced customers only. The different options settable here are referenced in the DSE documentation.

Parameters:

optionKey - the option's name.

optionValue - the option's value. The value is always a String and will be interpreted to the right type by the DSE server. To unset a value previously set you can put null as the option's value.

Returns:

this GraphStatement instance (for method chaining).

getGraphInternalOption

public String getGraphInternalOption(String optionKey)

Returns the advanced option's value defined for the key in parameter.

Parameters:

optionKey - the name of the option.

Returns:

the value. If no value has previously been set for the specified option name, or if a value has been set then unset with null (see setGraphInternalOption(java.lang.String, java.lang.String)), this method returns null.

setConsistencyLevel

public abstract GraphStatement setConsistencyLevel(ConsistencyLevel consistencyLevel)

Sets the consistency level to use for this statement.

This setting will affect the general consistency when executing the graph query. However executing a graph query on the server side is going to involve the execution of CQL queries to the persistence engine that is Cassandra. Those queries can be both reads and writes and both will have a settable consistency level. Setting only this property will indicate to the server to use this consistency level for both reads and writes in Cassandra. Read or write consistency level can be set separately with respectively setGraphReadConsistencyLevel(ConsistencyLevel) and setGraphWriteConsistencyLevel(ConsistencyLevel) and will override the consistency set here.

Parameters:

consistencyLevel - the consistency level to set.

Returns:

this GraphStatement instance (for method chaining).

getConsistencyLevel

public abstract ConsistencyLevel getConsistencyLevel()

Returns the consistency level to use with this statement.

This will return the consistency level used for reads and writes in Cassandra.

Please see setConsistencyLevel(ConsistencyLevel) for more information.

Returns:

the consistency level configured in this statement.

setDefaultTimestamp

public abstract GraphStatement setDefaultTimestamp(long defaultTimestamp)

Sets the default timestamp for this query (in microseconds since the epoch).

The actual timestamp that will be used for this query is, in order of preference:

• the timestamp specified through this method, if different from Long.MIN_VALUE;
• the timestamp returned by the TimestampGenerator currently in use, if different from Long.MIN_VALUE.

If none of these apply, no timestamp will be sent with the query and DseGraph will generate a server-side one.

Parameters:

defaultTimestamp - the default timestamp for this query (must be strictly positive).

Returns:

this GraphStatement instance (for method chaining).

See Also:

DseCluster.Builder.withTimestampGenerator(com.datastax.driver.core.TimestampGenerator)

getDefaultTimestamp

public abstract long getDefaultTimestamp()

The default timestamp for this query.

Returns:

the default timestamp (in microseconds since the epoch).

getReadTimeoutMillis

public abstract int getReadTimeoutMillis()

Return the per-host socket read timeout that was set for this statement.

Returns:

the timeout. A negative value means that the timeout has not been set on this statement; the default GraphOptions.getReadTimeoutMillis() will be used.

setReadTimeoutMillis

public abstract GraphStatement setReadTimeoutMillis(int readTimeoutMillis)

Overrides the default per-host read timeout (GraphOptions.setReadTimeoutMillis(int)) for this statement.

If you don't call this method, the default GraphOptions.getReadTimeoutMillis() will be used.

Parameters:

readTimeoutMillis - the timeout to set. 0 will disable the timeout for the query, negative values are not allowed.

Returns:

this GraphOptions instance (for method chaining).

executingAs

public GraphStatement executingAs(String userOrRole)

Allows this statement to be executed as a different user/role than the one currently authenticated (a.k.a. proxy execution).

This feature is only available in DSE 5.1+.

Parameters:

userOrRole - The user or role name to act as when executing this statement.

unwrap

public abstract Statement unwrap()

"Unwraps" the current graph statement, that is, returns an executable Statement object corresponding to this graph statement.

This method is intended for internal use only, users wishing to execute graph statements should use DseSession.executeGraph(GraphStatement).

This method acts as a bridge between graph statements and regular Statements.

Implementations are free to cache the returned Statement if appropriate.

Returns:

an executable Statement.

setTransformResultFunction

public GraphStatement setTransformResultFunction(Function<Row,GraphNode> transformResultFunction)

Sets the function to transform a Row to a GraphNode.

See getTransformResultFunction().

Parameters:

transformResultFunction - the function to set.

Returns:

this GraphStatement instance (for method chaining).

getTransformResultFunction

public Function<Row,GraphNode> getTransformResultFunction()

Allows users to input their own implementations of GraphNode directly into the DSE Driver's workflow. This method must return a function that will take as a input a Row from the underlying Apache Cassandra driver, and return an object in the type GraphNode.

Returns:

the function that returns a GraphNode implementation.