com.datastax.driver.core.querybuilder

Class Delete.Where

java.lang.Object

com.datastax.driver.core.Statement

com.datastax.driver.core.RegularStatement

com.datastax.driver.core.querybuilder.BuiltStatement

com.datastax.driver.core.querybuilder.Delete.Where

Enclosing class:

Delete

public static class Delete.Where
extends BuiltStatement

The WHERE clause of a DELETE statement.

Field Summary

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

idempotent, NULL_PAYLOAD_VALUE

Method Summary

Modifier and Type	Method and Description
Delete.Where	and(Clause clause) Adds the provided clause to this WHERE clause.
Statement	disableTracing() Disables tracing for this query.
Statement	enableTracing() Enables tracing for this query.
ConsistencyLevel	getConsistencyLevel() The consistency level for this query.
String	getKeyspace() Returns the keyspace this query operates on.
String	getQueryString(CodecRegistry codecRegistry) Returns the query string for this statement.
RetryPolicy	getRetryPolicy() Returns the retry policy sets for this query, if any.
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() Whether or not this statement has values, that is if getValues will return null or not.
Delete	ifExists() Sets the 'IF EXISTS' option for the DELETE statement this WHERE clause is part of.
boolean	isTracing() Returns whether tracing is enabled for this query or not.
Delete.Conditions	onlyIf(Clause condition) Adds a condition to the DELETE statement this WHERE clause is part of.
Statement	setConsistencyLevel(ConsistencyLevel consistency) Sets the consistency level for the query.
RegularStatement	setForceNoValues(boolean forceNoValues) Allows to force this builder to not generate values (through its getValues() method).
Statement	setRetryPolicy(RetryPolicy policy) Sets the retry policy to use for this query.
String	toString() Returns this statement as a CQL query string.
Delete.Options	using(Using using) Adds an option to the DELETE statement this WHERE clause is part of.

Methods inherited from class com.datastax.driver.core.querybuilder.BuiltStatement

escapeId, getNamedValues, getObject, getObject, hasValues, isIdempotent, usesNamedValues

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

getQueryString

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

getDefaultTimestamp, getFetchSize, getOutgoingPayload, getReadTimeoutMillis, getSerialConsistencyLevel, isBatchIdempotent, setDefaultTimestamp, setFetchSize, setIdempotent, setOutgoingPayload, setPagingState, setPagingState, setPagingStateUnsafe, setReadTimeoutMillis, setSerialConsistencyLevel

Methods inherited from class java.lang.Object

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

Method Detail

and

public Delete.Where and(Clause clause)

Adds the provided clause to this WHERE clause.

Parameters:

clause - the clause to add.

Returns:

this WHERE clause.

using

public Delete.Options using(Using using)

Adds an option to the DELETE statement this WHERE clause is part of.

Parameters:

using - the using clause to add.

Returns:

the options of the DELETE statement this WHERE clause is part of.

ifExists

public Delete ifExists()

Sets the 'IF EXISTS' option for the DELETE statement this WHERE clause is part of.

A delete with that option will report whether the statement actually resulted in data being deleted. The existence check and deletion are done transactionally in the sense that if multiple clients attempt to delete a given row with this option, then at most one may succeed.

Please keep in mind that using this option has a non negligible performance impact and should be avoided when possible.

Returns:

the DELETE statement this WHERE clause is part of.

onlyIf

public Delete.Conditions onlyIf(Clause condition)

Adds a condition to the DELETE statement this WHERE clause is part of.

Parameters:

condition - the condition to add.

Returns:

the conditions for the DELETE statement this WHERE clause is part of.

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.

Overrides:

getQueryString in class BuiltStatement

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()

getRoutingKey

public ByteBuffer getRoutingKey(ProtocolVersion protocolVersion,
                                CodecRegistry codecRegistry)

Description copied from class: Statement

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.

Overrides:

getRoutingKey in class BuiltStatement

Parameters:

protocolVersion - the protocol version that will be used if the actual implementation needs to serialize something to compute the key.

codecRegistry - the codec registry that will be used if the actual implementation needs to serialize something to compute this key.

Returns:

the routing key for this query or null.

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.

Overrides:

getKeyspace in class BuiltStatement

Returns:

the keyspace this query operate on if relevant or null.

setForceNoValues

public RegularStatement setForceNoValues(boolean forceNoValues)

Description copied from class: BuiltStatement

Allows to force this builder to not generate values (through its getValues() method).

By default (and unless the protocol version 1 is in use, see below) and for performance reasons, the query builder will not serialize all values provided to strings. This means that BuiltStatement.getQueryString(CodecRegistry) may return a query string with bind markers (where and when is at the discretion of the builder) and BuiltStatement.getValues(com.datastax.driver.core.ProtocolVersion, com.datastax.driver.core.CodecRegistry) will return the binary values for those markers. This method allows to force the builder to not generate binary values but rather to inline them all in the query string. In practice, this means that if you call setForceNoValues(true), you are guaranteed that getValues() will return null and that the string returned by getQueryString() will contain no other bind markers than the ones specified by the user.

If the native protocol version 1 is in use, the driver will default to not generating values since those are not supported by that version of the protocol. In practice, the driver will automatically call this method with true as argument prior to execution. Hence, calling this method when the protocol version 1 is in use is basically a no-op.

Note that this method is mainly useful for debugging purpose. In general, the default behavior should be the correct and most efficient one.

Overrides:

setForceNoValues in class BuiltStatement

Parameters:

forceNoValues - whether or not this builder may generate values.

Returns:

this statement.

setConsistencyLevel

public Statement setConsistencyLevel(ConsistencyLevel consistency)

Description copied from class: Statement

Sets the consistency level for the query.

Overrides:

setConsistencyLevel in class Statement

Parameters:

consistency - the consistency level to set.

Returns:

this Statement object.

getConsistencyLevel

public ConsistencyLevel getConsistencyLevel()

Description copied from class: Statement

The consistency level for this query.

Overrides:

getConsistencyLevel in class Statement

Returns:

the consistency level for this query, or null if no consistency level has been specified (through setConsistencyLevel). In the latter case, the default consistency level will be used.

enableTracing

public Statement enableTracing()

Description copied from class: Statement

Enables tracing for this query.

By default (that is unless you call this method), tracing is not enabled.

Overrides:

enableTracing in class Statement

Returns:

this Statement object.

disableTracing

public Statement disableTracing()

Description copied from class: Statement

Disables tracing for this query.

Overrides:

disableTracing in class Statement

Returns:

this Statement object.

isTracing

public boolean isTracing()

Description copied from class: Statement

Returns whether tracing is enabled for this query or not.

Overrides:

isTracing in class Statement

Returns:

true if this query has tracing enabled, false otherwise.

setRetryPolicy

public Statement setRetryPolicy(RetryPolicy policy)

Description copied from class: Statement

Sets the retry policy to use for this query.

The default retry policy, if this method is not called, is the one returned by Policies.getRetryPolicy() in the cluster configuration. This method is thus only useful in case you want to punctually override the default policy for this request.

Overrides:

setRetryPolicy in class Statement

Parameters:

policy - the retry policy to use for this query.

Returns:

this Statement object.

getRetryPolicy

public RetryPolicy getRetryPolicy()

Description copied from class: Statement

Returns the retry policy sets for this query, if any.

Overrides:

getRetryPolicy in class Statement

Returns:

the retry policy sets specifically for this query or null if no query specific retry policy has been set through Statement.setRetryPolicy(com.datastax.driver.core.policies.RetryPolicy) (in which case the Cluster retry policy will apply if necessary).

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).

Overrides:

getValues in class BuiltStatement

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.SimpleStatement(String, Object...)

hasValues

public boolean hasValues()

Description copied from class: RegularStatement

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

This method calls RegularStatement.hasValues(CodecRegistry) with ProtocolVersion.NEWEST_SUPPORTED. Whether you should use this or the other variant depends on the type of statement this is called on:

• for a SimpleStatement or SchemaStatement, the codec registry isn't actually needed, so it's always safe to use this method;
• for a BuiltStatement you can use this method if you use no custom codecs, or if your custom codecs are registered with the default registry. Otherwise, use the other method and provide the registry that contains your codecs (see BuiltStatement for more explanations on why this is so);
• for a BatchStatement, use the first rule if it contains no built statements, or the second rule otherwise.

Overrides:

hasValues in class RegularStatement

Returns:

false if RegularStatement.getValues(com.datastax.driver.core.ProtocolVersion, com.datastax.driver.core.CodecRegistry) returns null, true otherwise.

toString

public String toString()

Description copied from class: RegularStatement

Returns this statement as a CQL query string.

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.

See the javadocs of RegularStatement.getQueryString() for more information.

Overrides:

toString in class BuiltStatement

Returns:

this statement as a CQL query string.

See Also:

RegularStatement.getQueryString()