org.jpox.store.rdbms.query
Class JDOQLQuery

java.lang.Object
  org.jpox.store.query.Query
      org.jpox.store.query.AbstractJavaQuery
          org.jpox.store.query.AbstractJDOQLQuery
              org.jpox.store.rdbms.query.JDOQLQuery

All Implemented Interfaces:

java.io.Serializable

public class JDOQLQuery
extends org.jpox.store.query.AbstractJDOQLQuery

RDBMS representation of a JDOQL query for use by JPOX. The query can be specified via method calls, or via a single-string form.

Version:

$Revision: 1.40 $

See Also:

Query, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.jpox.store.query.Query

org.jpox.store.query.Query.SubqueryDefinition

Field Summary

protected org.jpox.store.mapped.query.Queryable	candidates Candidates for this query.
protected org.jpox.store.mapped.expression.QueryExpression	queryStmt The Query Statement.

Fields inherited from class org.jpox.store.query.AbstractJavaQuery

candidateCollection, candidateExtent, distinct, resultMetaData, rof, singleString, userDefinedScalarExpressions

Fields inherited from class org.jpox.store.query.Query

BULK_DELETE, BULK_UPDATE, candidateClass, candidateClassName, explicitParameters, explicitVariables, extensions, filter, from, fromInclNo, grouping, having, ignoreCache, implicitParameters, imports, isCompiled, LOCALISER, om, ordering, parameterNames, parsedImports, queryResults, range, result, resultClass, resultClassName, SELECT, subclasses, subqueries, toExclNo, type, unique, unmodifiable, update

Constructor Summary

JDOQLQuery(org.jpox.ObjectManager om)
Constructs a new query instance that uses the given persistence manager.

JDOQLQuery(org.jpox.ObjectManager om, JDOQLQuery q)
Constructs a new query instance having the same criteria as the given query.

JDOQLQuery(org.jpox.ObjectManager om, java.lang.String query)
Constructor for a JDOQL query where the query is specified using the "Single-String" format.

Method Summary

protected boolean	applyRangeChecks() Method to return if the query results should have the range checked and unnecessary rows discarded.
protected void	compileInternal(boolean forExecute, java.util.Map parameterValues) Method to compile the query.
protected void	discardCompiled() Method to discard our current compiled query due to changes.
boolean	equals(java.lang.Object obj) Equality operator for JDOQL.
org.jpox.store.mapped.query.Queryable	getCandidates() Accessor for the candidates for the query.
protected org.jpox.store.mapped.query.Evaluator	getEvaluator(org.jpox.ObjectManager om, boolean distinct, org.jpox.store.query.Query query, org.jpox.store.query.ResultObjectFactory rof, java.util.Collection candidateCollection) Method to return the evaluator to use for this JDOQL query.
protected java.lang.Object	performExecute(java.util.Map parameters) Execute the query and return the filtered QueryResult.
protected boolean	shouldReturnSingleRow() Convenience method to return whether the query should return a single row.

Methods inherited from class org.jpox.store.query.AbstractJDOQLQuery

getSingleStringQuery, performDeletePersistentAll, setGrouping

Methods inherited from class org.jpox.store.query.AbstractJavaQuery

getCandidateCollection, getCandidateExtent, getParsedImports, getResultSetMetaData, getUserDefinedScalarExpressions, registerScalarExpression, registerScalarExpressions, resultHasOnlyAggregates, setCandidates, setCandidates, toString

Methods inherited from class org.jpox.store.query.Query

addExtension, addSubquery, assertIsModifiable, close, closeAll, compile, declareExplicitParameters, declareExplicitVariables, declareImports, deletePersistentAll, deletePersistentAll, deletePersistentAll, execute, execute, execute, execute, executeWithArray, executeWithMap, getCandidateClass, getCandidateClassName, getExplicitParameters, getExplicitVariables, getExtension, getFetchPlan, getFilter, getFrom, getGrouping, getHaving, getIgnoreCache, getImports, getObjectManager, getOrdering, getRange, getRangeFromIncl, getRangeToExcl, getResult, getResultClass, getResultClassName, getStoreManager, getSubqueryForVariable, getType, getUpdate, hashCode, hasSubqueryForVariable, isCompiled, isSubclasses, isUnique, isUnmodifiable, prepareDatastore, resolveClassDeclaration, setCandidateClassName, setClass, setExtensions, setFetchPlan, setFilter, setFrom, setHaving, setIgnoreCache, setImplicitParameter, setImplicitParameter, setOrdering, setRange, setRange, setResult, setResultClass, setResultClassName, setResultMetaData, setSubclasses, setType, setUnique, setUnmodifiable, setUpdate

Methods inherited from class java.lang.Object

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

Field Detail

queryStmt

protected transient org.jpox.store.mapped.expression.QueryExpression queryStmt

The Query Statement.

candidates

protected transient org.jpox.store.mapped.query.Queryable candidates

Candidates for this query.

Constructor Detail

JDOQLQuery

public JDOQLQuery(org.jpox.ObjectManager om)

Constructs a new query instance that uses the given persistence manager.

Parameters:

om - the associated ObjectManager for this query.

JDOQLQuery

public JDOQLQuery(org.jpox.ObjectManager om,
                  JDOQLQuery q)

Constructs a new query instance having the same criteria as the given query.

Parameters:

om - The ObjectManager

q - The query from which to copy criteria.

JDOQLQuery

public JDOQLQuery(org.jpox.ObjectManager om,
                  java.lang.String query)

Constructor for a JDOQL query where the query is specified using the "Single-String" format.

Parameters:

om - The persistence manager

query - The query string

Method Detail

getCandidates

public org.jpox.store.mapped.query.Queryable getCandidates()

Accessor for the candidates for the query. This is only valid after compiling the query.

Returns:

Candidates for the query

equals

public boolean equals(java.lang.Object obj)

Equality operator for JDOQL.

Overrides:

equals in class org.jpox.store.query.Query

See Also:

Object.equals(java.lang.Object)

compileInternal

protected void compileInternal(boolean forExecute,
                               java.util.Map parameterValues)

Method to compile the query.

Specified by:

compileInternal in class org.jpox.store.query.Query

Parameters:

forExecute - Whether to compile ready for execution

discardCompiled

protected void discardCompiled()

Method to discard our current compiled query due to changes.

Overrides:

discardCompiled in class org.jpox.store.query.AbstractJavaQuery

See Also:

Query.discardCompiled()

shouldReturnSingleRow

protected boolean shouldReturnSingleRow()

Convenience method to return whether the query should return a single row.

Specified by:

shouldReturnSingleRow in class org.jpox.store.query.Query

Returns:

Whether a single row should result

performExecute

protected java.lang.Object performExecute(java.util.Map parameters)

Execute the query and return the filtered QueryResult.

Specified by:

performExecute in class org.jpox.store.query.Query

Parameters:

parameters - Map containing all of the parameters.

Returns:

the filtered QueryResult.

getEvaluator

protected org.jpox.store.mapped.query.Evaluator getEvaluator(org.jpox.ObjectManager om,
                                                             boolean distinct,
                                                             org.jpox.store.query.Query query,
                                                             org.jpox.store.query.ResultObjectFactory rof,
                                                             java.util.Collection candidateCollection)

Method to return the evaluator to use for this JDOQL query.

Parameters:

query - The query

distinct - whether to return distinct results

rof - ResultObjectFactory

candidateCollection - Any candidate collection

Returns:

The evaluator

applyRangeChecks

protected boolean applyRangeChecks()

Method to return if the query results should have the range checked and unnecessary rows discarded. This is for where the query language has specified a range but the datastore doesnt allow removal of unnecessary results in the query itself (so has to be done in post-processing). This implementation returns false and so should be overridden by query languages to match their capabilities.

Overrides:

applyRangeChecks in class org.jpox.store.query.Query

Returns:

Whether to apply range checks in post-processing of results.