org.apache.cassandra.cql3.statements

Class SelectStatement

java.lang.Object

org.apache.cassandra.cql3.statements.SelectStatement

All Implemented Interfaces:

CQLStatement

public class SelectStatement
extends java.lang.Object
implements CQLStatement

Encapsulates a completely parsed SELECT query, including the target column family, expression, result count, and ordering clause. A number of public methods here are only used internally. However, many of these are made accessible for the benefit of custom QueryHandler implementations, so before reducing their accessibility due consideration should be given.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SelectStatement.Parameters
static class	SelectStatement.RawStatement

Field Summary

Fields

Modifier and Type	Field and Description
CFMetaData	cfm
static int	DEFAULT_PAGE_SIZE
SelectStatement.Parameters	parameters

Constructor Summary

Constructors

Constructor and Description
SelectStatement(CFMetaData cfm, int boundTerms, SelectStatement.Parameters parameters, Selection selection, StatementRestrictions restrictions, boolean isReversed, AggregationSpecification aggregationSpec, java.util.Comparator<java.util.List<java.nio.ByteBuffer>> orderingComparator, Term limit, Term perPartitionLimit)

Method Summary

Modifier and Type	Method and Description
void	checkAccess(ClientState state) Perform any access verification necessary for the statement.
Slices	clusteringIndexFilterAsSlices() Returns the slices fetched by this SELECT, assuming an internal call (no bound values in particular).
java.lang.String	columnFamily()
ResultMessage.Rows	execute(QueryState state, QueryOptions options, long queryStartNanoTime) Execute the statement and return the resulting result or null if there is no result.
ResultMessage.Rows	executeInternal(QueryState state, QueryOptions options) Variant of execute used for internal query against the system tables, and thus only query the local node.
ResultMessage.Rows	executeInternal(QueryState state, QueryOptions options, int nowInSec, long queryStartNanoTime)
int	getBoundTerms() Returns the number of bound terms in this statement.
static java.nio.ByteBuffer[]	getComponents(CFMetaData cfm, DecoratedKey dk)
java.lang.Iterable<Function>	getFunctions() Return an Iterable over all of the functions (both native and user-defined) used by any component of the statement
int	getLimit(QueryOptions options) Returns the limit specified by the user.
int	getPerPartitionLimit(QueryOptions options) Returns the per partition limit specified by the user.
ReadQuery	getQuery(QueryOptions options, int nowInSec)
ReadQuery	getQuery(QueryOptions options, int nowInSec, int userLimit, int perPartitionLimit, int pageSize)
StatementRestrictions	getRestrictions() May be used by custom QueryHandler implementations
ResultSet.ResultMetadata	getResultMetadata()
RowFilter	getRowFilter(QueryOptions options) May be used by custom QueryHandler implementations
Selection	getSelection() May be used by custom QueryHandler implementations
SinglePartitionReadCommand	internalReadForView(DecoratedKey key, int nowInSec) Returns a read command that can be used internally to query all the rows queried by this SELECT for a give key (used for materialized views).
java.lang.String	keyspace()
ResultSet	process(PartitionIterator partitions, int nowInSec)
ColumnFilter	queriedColumns() The columns to fetch internally for this SELECT statement (which can be more than the one selected by the user as it also include any restricted column in particular).
RowFilter	rowFilterForInternalCalls() The RowFilter for this SELECT, assuming an internal call (no bound values in particular).
void	validate(ClientState state) Perform additional validation required by the statment.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

See Also:

Constant Field Values

cfm

public final CFMetaData cfm

parameters

public final SelectStatement.Parameters parameters

Constructor Detail

SelectStatement

public SelectStatement(CFMetaData cfm,
                       int boundTerms,
                       SelectStatement.Parameters parameters,
                       Selection selection,
                       StatementRestrictions restrictions,
                       boolean isReversed,
                       AggregationSpecification aggregationSpec,
                       java.util.Comparator<java.util.List<java.nio.ByteBuffer>> orderingComparator,
                       Term limit,
                       Term perPartitionLimit)

Method Detail

getFunctions

public java.lang.Iterable<Function> getFunctions()

Description copied from interface: CQLStatement

Return an Iterable over all of the functions (both native and user-defined) used by any component of the statement

Specified by:

getFunctions in interface CQLStatement

Returns:

functions all functions found (may contain duplicates)

queriedColumns

public ColumnFilter queriedColumns()

The columns to fetch internally for this SELECT statement (which can be more than the one selected by the user as it also include any restricted column in particular).

getResultMetadata

public ResultSet.ResultMetadata getResultMetadata()

getBoundTerms

public int getBoundTerms()

Description copied from interface: CQLStatement

Returns the number of bound terms in this statement.

Specified by:

getBoundTerms in interface CQLStatement

checkAccess

public void checkAccess(ClientState state)
                 throws InvalidRequestException,
                        UnauthorizedException

Description copied from interface: CQLStatement

Perform any access verification necessary for the statement.

Specified by:

checkAccess in interface CQLStatement

Parameters:

state - the current client state

Throws:

InvalidRequestException

UnauthorizedException

validate

public void validate(ClientState state)
              throws InvalidRequestException

Description copied from interface: CQLStatement

Perform additional validation required by the statment. To be overriden by subclasses if needed.

Specified by:

validate in interface CQLStatement

Parameters:

state - the current client state

Throws:

InvalidRequestException

execute

public ResultMessage.Rows execute(QueryState state,
                                  QueryOptions options,
                                  long queryStartNanoTime)
                           throws RequestExecutionException,
                                  RequestValidationException

Description copied from interface: CQLStatement

Execute the statement and return the resulting result or null if there is no result.

Specified by:

execute in interface CQLStatement

Parameters:

state - the current query state

options - options for this query (consistency, variables, pageSize, ...)

queryStartNanoTime - the timestamp returned by System.nanoTime() when this statement was received

Throws:

RequestExecutionException

RequestValidationException

getQuery

public ReadQuery getQuery(QueryOptions options,
                          int nowInSec)
                   throws RequestValidationException

Throws:

RequestValidationException

getQuery

public ReadQuery getQuery(QueryOptions options,
                          int nowInSec,
                          int userLimit,
                          int perPartitionLimit,
                          int pageSize)

executeInternal

public ResultMessage.Rows executeInternal(QueryState state,
                                          QueryOptions options)
                                   throws RequestExecutionException,
                                          RequestValidationException

Description copied from interface: CQLStatement

Variant of execute used for internal query against the system tables, and thus only query the local node.

Specified by:

executeInternal in interface CQLStatement

Parameters:

state - the current query state

Throws:

RequestExecutionException

RequestValidationException

executeInternal

public ResultMessage.Rows executeInternal(QueryState state,
                                          QueryOptions options,
                                          int nowInSec,
                                          long queryStartNanoTime)
                                   throws RequestExecutionException,
                                          RequestValidationException

Throws:

RequestExecutionException

RequestValidationException

process

public ResultSet process(PartitionIterator partitions,
                         int nowInSec)
                  throws InvalidRequestException

Throws:

InvalidRequestException

keyspace

public java.lang.String keyspace()

columnFamily

public java.lang.String columnFamily()

getSelection

public Selection getSelection()

May be used by custom QueryHandler implementations

getRestrictions

public StatementRestrictions getRestrictions()

May be used by custom QueryHandler implementations

clusteringIndexFilterAsSlices

public Slices clusteringIndexFilterAsSlices()

Returns the slices fetched by this SELECT, assuming an internal call (no bound values in particular).

Note that if the SELECT intrinsically selects rows by names, we convert them into equivalent slices for the purpose of this method. This is used for MVs to restrict what needs to be read when we want to read everything that could be affected by a given view (and so, if the view SELECT statement has restrictions on the clustering columns, we can restrict what we read).

internalReadForView

public SinglePartitionReadCommand internalReadForView(DecoratedKey key,
                                                      int nowInSec)

Returns a read command that can be used internally to query all the rows queried by this SELECT for a give key (used for materialized views).

rowFilterForInternalCalls

public RowFilter rowFilterForInternalCalls()

The RowFilter for this SELECT, assuming an internal call (no bound values in particular).

getLimit

public int getLimit(QueryOptions options)

Returns the limit specified by the user. May be used by custom QueryHandler implementations

Returns:

the limit specified by the user or DataLimits.NO_LIMIT if no value as been specified.

getPerPartitionLimit

public int getPerPartitionLimit(QueryOptions options)

Returns the per partition limit specified by the user. May be used by custom QueryHandler implementations

Returns:

the per partition limit specified by the user or DataLimits.NO_LIMIT if no value as been specified.

getRowFilter

public RowFilter getRowFilter(QueryOptions options)
                       throws InvalidRequestException

May be used by custom QueryHandler implementations

Throws:

InvalidRequestException

getComponents

public static java.nio.ByteBuffer[] getComponents(CFMetaData cfm,
                                                  DecoratedKey dk)