com.datastax.driver.core.schemabuilder

Class SchemaStatement

java.lang.Object

com.datastax.driver.core.Statement

com.datastax.driver.core.RegularStatement

com.datastax.driver.core.schemabuilder.SchemaStatement

Direct Known Subclasses:

AbstractCreateStatement, Drop, DropKeyspace, KeyspaceOptions, TableOptions

public abstract class SchemaStatement
extends RegularStatement

A DDL statement generated by SchemaBuilder.

Field Summary

Fields inherited from class com.datastax.driver.core.Statement

idempotent, NULL_PAYLOAD_VALUE

Constructor Summary

Constructors

Constructor and Description
SchemaStatement()

Method Summary

Modifier and Type	Method and Description
String	getKeyspace() Returns the keyspace this query operates on.
Map<String,ByteBuffer>	getNamedValues(ProtocolVersion protocolVersion, CodecRegistry codecRegistry) The named values to use for this statement.
String	getQueryString(CodecRegistry codecRegistry) Returns the query string for this statement.
ByteBuffer	getRoutingKey(ProtocolVersion protocolVersion, CodecRegistry codecRegistry) Returns the routing key (in binary raw form) to use for token aware routing of this query.
ByteBuffer[]	getValues(ProtocolVersion protocolVersion, CodecRegistry codecRegistry) The positional values to use for this statement.
boolean	hasValues(CodecRegistry codecRegistry) Whether or not this statement has values, that is if getValues will return null or not.
boolean	usesNamedValues() Whether this statement uses named values.

Methods inherited from class com.datastax.driver.core.RegularStatement

getQueryString, hasValues, requestSizeInBytes, toString

Methods inherited from class com.datastax.driver.core.Statement

disableTracing, enableTracing, getConsistencyLevel, getDefaultTimestamp, getFetchSize, getHost, getNowInSeconds, getOutgoingPayload, getReadTimeoutMillis, getRetryPolicy, getSerialConsistencyLevel, isBatchIdempotent, isIdempotent, isTracing, setConsistencyLevel, setDefaultTimestamp, setFetchSize, setHost, setIdempotent, setNowInSeconds, setOutgoingPayload, setPagingState, setPagingState, setPagingStateUnsafe, setReadTimeoutMillis, setRetryPolicy, setSerialConsistencyLevel

Methods inherited from class java.lang.Object

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

Constructor Detail

SchemaStatement

public SchemaStatement()

Method Detail

getQueryString

public String getQueryString(CodecRegistry codecRegistry)

Description copied from class: RegularStatement

Returns the query string for this statement.

It is important to note that the query string is merely a CQL representation of this statement, but it does not convey all the information stored in Statement objects.

For example, Statement objects carry numerous protocol-level settings, such as the consistency level to use, or the idempotence flag, among others. None of these settings will be included in the resulting query string.

Similarly, if values have been set on this statement because it has bind markers, these values will not appear in the resulting query string.

Note: the consistency level was conveyed at CQL level in older versions of the CQL grammar, but since CASSANDRA-4734 it is now a protocol-level setting and consequently does not appear in the query string.

Specified by:

getQueryString in class RegularStatement

Parameters:

codecRegistry - the codec registry that will be used if the actual implementation needs to serialize Java objects in the process of generating the query. Note that it might be possible to use the no-arg RegularStatement.getQueryString() depending on the type of statement this is called on.

Returns:

a valid CQL query string.

See Also:

RegularStatement.getQueryString()

getValues

public ByteBuffer[] getValues(ProtocolVersion protocolVersion,
                              CodecRegistry codecRegistry)

Description copied from class: RegularStatement

The positional values to use for this statement.

A statement can use either positional or named values, but not both. So if this method returns a non-null result, RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry) will return null.

Values for a RegularStatement (i.e. if either method does not return null) are not supported with the native protocol version 1: you will get an UnsupportedProtocolVersionException when submitting one if version 1 of the protocol is in use (i.e. if you've forced version 1 through Cluster.Builder.withProtocolVersion(com.datastax.driver.core.ProtocolVersion) or you use Cassandra 1.2).

Specified by:

getValues in class RegularStatement

Parameters:

protocolVersion - the protocol version that will be used to serialize the values.

codecRegistry - the codec registry that will be used to serialize the values.

See Also:

SimpleStatement(String, Object...)

hasValues

public boolean hasValues(CodecRegistry codecRegistry)

Description copied from class: RegularStatement

Whether or not this statement has values, that is if getValues will return null or not.

Specified by:

hasValues in class RegularStatement

Parameters:

codecRegistry - the codec registry that will be used if the actual implementation needs to serialize Java objects in the process of determining if the query has values. Note that it might be possible to use the no-arg RegularStatement.hasValues() depending on the type of statement this is called on.

Returns:

false if both RegularStatement.getValues(ProtocolVersion, CodecRegistry) and RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry) return null, true otherwise.

See Also:

RegularStatement.hasValues()

getNamedValues

public Map<String,ByteBuffer> getNamedValues(ProtocolVersion protocolVersion,
                                             CodecRegistry codecRegistry)

Description copied from class: RegularStatement

The named values to use for this statement.

A statement can use either positional or named values, but not both. So if this method returns a non-null result, RegularStatement.getValues(ProtocolVersion, CodecRegistry) will return null.

Values for a RegularStatement (i.e. if either method does not return null) are not supported with the native protocol version 1: you will get an UnsupportedProtocolVersionException when submitting one if version 1 of the protocol is in use (i.e. if you've forced version 1 through Cluster.Builder.withProtocolVersion(com.datastax.driver.core.ProtocolVersion) or you use Cassandra 1.2).

Specified by:

getNamedValues in class RegularStatement

Parameters:

protocolVersion - the protocol version that will be used to serialize the values.

codecRegistry - the codec registry that will be used to serialize the values.

Returns:

the named values.

See Also:

SimpleStatement(String, Map)

usesNamedValues

public boolean usesNamedValues()

Description copied from class: RegularStatement

Whether this statement uses named values.

Specified by:

usesNamedValues in class RegularStatement

Returns:

false if RegularStatement.getNamedValues(ProtocolVersion, CodecRegistry) returns null, true otherwise.

getKeyspace

public String getKeyspace()

Description copied from class: Statement

Returns the keyspace this query operates on.

Note that not all query specify on which keyspace they operate on, and so this method can always return null. Firstly, some queries do not operate inside a keyspace: keyspace creation, USE queries, user creation, etc. Secondly, even query that operate within a keyspace do not have to specify said keyspace directly, in which case the currently logged in keyspace (the one set through a USE query (or through the use of Cluster.connect(String))). Lastly, as for the routing key, this keyspace information is only a hint for token-aware routing (since replica placement depend on the replication strategy in use which is a per-keyspace property) and having this method return null (or even a bogus keyspace name) will never cause the query to fail.

Specified by:

getKeyspace in class Statement

Returns:

the keyspace this query operate on if relevant or null.

getRoutingKey

public ByteBuffer getRoutingKey(ProtocolVersion protocolVersion,
                                CodecRegistry codecRegistry)

Returns the routing key (in binary raw form) to use for token aware routing of this query.

The routing key is optional in that implementers are free to return null. The routing key is an hint used for token-aware routing (see TokenAwarePolicy), and if provided should correspond to the binary value for the query partition key. However, not providing a routing key never causes a query to fail and if the load balancing policy used is not token aware, then the routing key can be safely ignored.

Specified by:

getRoutingKey in class Statement

Parameters:

protocolVersion - unused by this implementation (the key is always null for schema statements).

codecRegistry - unused by this implementation (the key is always null for schema statements).

Returns:

the routing key for this query or null.