org.teiid.query.sql.lang

Class Query

java.lang.Object

org.teiid.query.sql.lang.Command

org.teiid.query.sql.lang.QueryCommand

org.teiid.query.sql.lang.Query

All Implemented Interfaces:

Cloneable, FilteredCommand, LanguageObject

public class Query
extends QueryCommand
implements FilteredCommand

A representation of a data query. A query consists of various parts, referred to as clauses. The following list the types of clauses that a query can hold, and their purpose:

      CLAUSE          PURPOSE
      =========       ==============================================
      Select          Defines the variables data to be retrieved for
        From            Defines the groups to retrieve data from
      Criteria        Defines constraints on data retrieval ("where")
         GroupBy            Defines how rows being returned should be grouped
         Having            Defines how groups should be filtered, also a criteria
      OrderBy         Defines how the results should be sorted
         Option            Defines any extra options on the query
 

Nested Class Summary

Nested classes/interfaces inherited from interface org.teiid.query.sql.LanguageObject

LanguageObject.Util

Field Summary

Fields inherited from class org.teiid.query.sql.lang.Command

tempGroupIDs, TYPE_ALTER_PROC, TYPE_ALTER_TRIGGER, TYPE_ALTER_VIEW, TYPE_BATCHED_UPDATE, TYPE_CREATE, TYPE_DELETE, TYPE_DROP, TYPE_DYNAMIC, TYPE_EXPLAIN, TYPE_INSERT, TYPE_QUERY, TYPE_SOURCE_EVENT, TYPE_STORED_PROCEDURE, TYPE_TRIGGER_ACTION, TYPE_UNKNOWN, TYPE_UPDATE, TYPE_UPDATE_PROCEDURE

Constructor Summary

Constructors

Constructor and Description
Query() Constructs a default instance of this class.
Query(Select select, From from, Criteria criteria, GroupBy groupBy, Criteria having, OrderBy orderBy, Option option) Constructs an instance of this class given all the clauses
Query(Select select, From from, Criteria criteria, OrderBy orderBy, Option option) Constructs an instance of this class given the specified clauses

Method Summary

Modifier and Type	Method and Description
void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
static boolean	areColumnsCachable(Collection<? extends Expression> projectedSymbols)
boolean	areResultsCachable() Whether the results are cachable.
void	clearCriteria() Set the criteria clause to null
Object	clone() Deep clone Query to produce a new identical query.
boolean	equals(Object obj) Compare two queries for equality.
Criteria	getCriteria() Get the criteria clause for the query.
From	getFrom() Get the from clause for the query.
GroupBy	getGroupBy() Get the group by clause for the query.
Criteria	getHaving() Get the having clause for the query.
Into	getInto()
Query	getProjectedQuery()
List<Expression>	getProjectedSymbols() Get the ordered list of all elements returned by this query.
Select	getSelect() Get the select clause for the query.
int	getType() Return type of command.
boolean	hasAggregates()
int	hashCode() Get hashcode for query.
boolean	isRowConstructor()
boolean	returnsResultSet()
static Query	rowConstructor(List<Expression> select)
void	setCriteria(Criteria criteria) Set the criteria clause for the query.
void	setFrom(From from) Set the from clause for the query.
void	setGroupBy(GroupBy groupBy) Set the group by clause for the query.
void	setHaving(Criteria having) Set the criteria clause for the query.
void	setInto(Into into)
void	setRowConstructor(boolean isRowConstructor)
void	setSelect(Select select) Set the select clause for the query.

Methods inherited from class org.teiid.query.sql.lang.QueryCommand

getLimit, getOrderBy, getWith, setLimit, setOrderBy, setWith

Methods inherited from class org.teiid.query.sql.lang.Command

addExternalGroupToContext, copyMetadataState, getActualCommand, getAllExternalGroups, getCacheHint, getCommandToken, getCorrelatedReferences, getExternalGroupContexts, getOption, getProcessorPlan, getResultSetColumns, getSourceHint, getTemporaryMetadata, getUpdateCommandSymbol, printCommandTree, printCommandTree, pushNewResolvingContext, sameOptionAndHint, setCacheHint, setCorrelatedReferences, setExternalGroupContexts, setOption, setProcessorPlan, setSourceHint, setTemporaryMetadata, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Query

public Query()

Constructs a default instance of this class.

Query

public Query(Select select,
             From from,
             Criteria criteria,
             OrderBy orderBy,
             Option option)

Constructs an instance of this class given the specified clauses

Parameters:

select - SELECT clause

from - FROM clause

criteria - WHERE clause

orderBy - ORDER BY clause

option - OPTION clause

Query

public Query(Select select,
             From from,
             Criteria criteria,
             GroupBy groupBy,
             Criteria having,
             OrderBy orderBy,
             Option option)

Constructs an instance of this class given all the clauses

Parameters:

select - SELECT clause

from - FROM clause

criteria - WHERE clause

groupBy - GROUP BY clause

having - HAVING clause

orderBy - ORDER BY clause

option - OPTION clause

Method Detail

rowConstructor

public static Query rowConstructor(List<Expression> select)

getType

public int getType()

Return type of command.

Specified by:

getType in class Command

Returns:

TYPE_QUERY

getSelect

public Select getSelect()

Get the select clause for the query.

Returns:

SELECT clause

setSelect

public void setSelect(Select select)

Set the select clause for the query.

Parameters:

select - SELECT clause

getFrom

public From getFrom()

Get the from clause for the query.

Returns:

FROM clause

setFrom

public void setFrom(From from)

Set the from clause for the query.

Parameters:

from - FROM clause

getCriteria

public Criteria getCriteria()

Get the criteria clause for the query.

Specified by:

getCriteria in interface FilteredCommand

Returns:

WHERE clause

setCriteria

public void setCriteria(Criteria criteria)

Set the criteria clause for the query.

Specified by:

setCriteria in interface FilteredCommand

Parameters:

criteria - WHERE clause

clearCriteria

public void clearCriteria()

Set the criteria clause to null

getGroupBy

public GroupBy getGroupBy()

Get the group by clause for the query.

Returns:

GROUP BY clause

setGroupBy

public void setGroupBy(GroupBy groupBy)

Set the group by clause for the query.

Parameters:

groupBy - GROUP BY clause

getHaving

public Criteria getHaving()

Get the having clause for the query.

Returns:

HAVING clause

setHaving

public void setHaving(Criteria having)

Set the criteria clause for the query.

Parameters:

having - HAVING clause

getInto

public Into getInto()

Returns:

setInto

public void setInto(Into into)

Parameters:

into -

acceptVisitor

public void acceptVisitor(LanguageVisitor visitor)

Description copied from interface: LanguageObject

Method for accepting a visitor. It is the responsibility of the language object to call back on the visitor.

Specified by:

acceptVisitor in interface LanguageObject

Parameters:

visitor - Visitor being used

getProjectedSymbols

public List<Expression> getProjectedSymbols()

Get the ordered list of all elements returned by this query. These elements may be ElementSymbols or ExpressionSymbols but in all cases each represents a single column.

Specified by:

getProjectedSymbols in class Command

Returns:

Ordered list of SingleElementSymbol

clone

public Object clone()

Deep clone Query to produce a new identical query.

Specified by:

clone in interface LanguageObject

Specified by:

clone in class Command

Returns:

Deep clone

equals

public boolean equals(Object obj)

Compare two queries for equality. Queries will only evaluate to equal if they are IDENTICAL: select variables are in the same order, criteria are in the same exact structure.

Overrides:

equals in class Object

Parameters:

obj - Other object

Returns:

True if equal

hashCode

public int hashCode()

Get hashcode for query. WARNING: This hash code relies on the hash codes of the Select and Criteria clauses. If the query changes, it's hash code will change and it can be lost from collections. Hash code is only valid after query has been completely constructed.

Overrides:

hashCode in class Object

Returns:

Hash code

areResultsCachable

public boolean areResultsCachable()

Description copied from class: Command

Whether the results are cachable.

Specified by:

areResultsCachable in class Command

Returns:

True if the results are cachable; false otherwise.

See Also:

Command.areResultsCachable()

areColumnsCachable

public static boolean areColumnsCachable(Collection<? extends Expression> projectedSymbols)

getProjectedQuery

public Query getProjectedQuery()

Specified by:

getProjectedQuery in class QueryCommand

See Also:

QueryCommand.getProjectedQuery()

returnsResultSet

public boolean returnsResultSet()

Overrides:

returnsResultSet in class QueryCommand

hasAggregates

public boolean hasAggregates()

isRowConstructor

public boolean isRowConstructor()

setRowConstructor

public void setRowConstructor(boolean isRowConstructor)