com.metamatrix.query.sql.lang
Class Query

java.lang.Object
  com.metamatrix.query.sql.lang.Command
      com.metamatrix.query.sql.lang.QueryCommand
          com.metamatrix.query.sql.lang.Query

All Implemented Interfaces:

LanguageObject, java.io.Serializable, java.lang.Cloneable

public class Query
extends QueryCommand

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
 

See Also:

Serialized Form

Field Summary

Fields inherited from class com.metamatrix.query.sql.lang.Command

tempGroupIDs, TYPE_BATCHED_UPDATE, TYPE_CREATE, TYPE_DELETE, TYPE_DROP, TYPE_DYNAMIC, TYPE_INSERT, TYPE_QUERY, TYPE_SQL, TYPE_STORED_PROCEDURE, TYPE_UNKNOWN, TYPE_UPDATE, TYPE_UPDATE_PROCEDURE, TYPE_XQUERY

Constructor Summary

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

void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
boolean	areResultsCachable() Whether the results are cachable.
void	clearCriteria() Set the criteria clause to null
java.lang.Object	clone() Deep clone Query to produce a new identical query.
boolean	equals(java.lang.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()
boolean	getIsXML() Get the xml flag for the query
Query	getProjectedQuery()
java.util.List	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.
int	hashCode() Get hashcode for query.
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	setIsXML(boolean isXML) Get the xml flag for the query
void	setSelect(Select select) Set the select clause for the query.
int	updatingModelCount(QueryMetadataInterface metadata) Return the number of updates on physical sources by this command.

Methods inherited from class com.metamatrix.query.sql.lang.QueryCommand

getLimit, getOrderBy, setLimit, setOrderBy

Methods inherited from class com.metamatrix.query.sql.lang.Command

addExternalGroupsToContext, addExternalGroupToContext, copyMetadataState, getAllExternalGroups, getCorrelatedReferences, getExternalGroupContexts, getOption, getProcessorPlan, getSubCommands, getSubCommandsUpdatingModelCount, getSubCommandsUpdatingModelCount, getTemporaryMetadata, getUpdateCommandSymbol, getVirtualGroup, isResolved, printCommandTree, printCommandTree, pushNewResolvingContext, setCorrelatedReferences, setExternalGroupContexts, setIsResolved, setOption, setProcessorPlan, setTemporaryMetadata, setVirtualGroup, 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

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

getIsXML

public boolean getIsXML()

Get the xml flag for the query

Returns:

boolean

setIsXML

public void setIsXML(boolean isXML)

Get the xml flag for the query

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.

Returns:

WHERE clause

setCriteria

public void setCriteria(Criteria criteria)

Set the criteria clause for the query.

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.

Parameters:

visitor - Visitor being used

getProjectedSymbols

public java.util.List 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 java.lang.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(java.lang.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 java.lang.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 java.lang.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()

updatingModelCount

public int updatingModelCount(QueryMetadataInterface metadata)
                       throws MetaMatrixComponentException

Description copied from class: Command

Return the number of updates on physical sources by this command.

Specified by:

updatingModelCount in class Command

Parameters:

metadata - QueryMetadataInterface

Returns:

The number of updates on physical sources by this command.

Throws:

MetaMatrixComponentException

getProjectedQuery

public Query getProjectedQuery()

Specified by:

getProjectedQuery in class QueryCommand

See Also:

QueryCommand.getProjectedQuery()