org.datanucleus.store.rdbms.query
Class ResultExpressionsQueryable

java.lang.Object
  org.datanucleus.store.rdbms.query.ResultExpressionsQueryable

All Implemented Interfaces:

org.datanucleus.store.mapped.expression.Queryable

public class ResultExpressionsQueryable
extends java.lang.Object
implements org.datanucleus.store.mapped.expression.Queryable

Result expressions to be returned by the query. The results might be fields of persistent instances, instances of classes other than the candidate class, or aggregates of fields.

Field Summary

protected static org.datanucleus.util.Localiser

LOCALISER

Constructor Summary

ResultExpressionsQueryable(org.datanucleus.ObjectManager om, java.lang.Class candidateClass, boolean subclasses)
Constructor.

ResultExpressionsQueryable(org.datanucleus.ObjectManager om, java.lang.Class candidateClass, java.util.Collection userCandidates, boolean subclasses)
Constructor.

Method Summary

org.datanucleus.store.mapped.expression.ScalarExpression[]	getResultExpressions()
boolean	hasAggregatedExpressionsOnly() Whether only aggregated expressions are returned
boolean	isEmpty() Returns true if this collection contains no elements.
org.datanucleus.store.mapped.expression.QueryExpression	newQueryStatement() Create a new query to search for the candidate classes etc.
org.datanucleus.store.mapped.expression.QueryExpression	newQueryStatement(java.lang.Class candidateClass, org.datanucleus.store.mapped.DatastoreIdentifier candidateAlias) Create a query to search for the candidateClass and subclasses if true
org.datanucleus.store.query.ResultObjectFactory	newResultObjectFactory(org.datanucleus.store.mapped.expression.QueryExpression stmt, boolean ignoreCache, java.lang.Class resultClass, boolean useFetchPlan)
void	setHasAggregatedExpressionsOnly(boolean flag) Convenience method to set if we know there are only aggregate expressions and so can ignore any checks on the result expressions.
void	setResultExpressions(org.datanucleus.store.mapped.expression.ScalarExpression[] expressions)

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final org.datanucleus.util.Localiser LOCALISER

Constructor Detail

ResultExpressionsQueryable

public ResultExpressionsQueryable(org.datanucleus.ObjectManager om,
                                  java.lang.Class candidateClass,
                                  boolean subclasses)

Constructor.

Parameters:

om - Object Manager

candidateClass - The candidate

subclasses - Whether to include subclasses

ResultExpressionsQueryable

public ResultExpressionsQueryable(org.datanucleus.ObjectManager om,
                                  java.lang.Class candidateClass,
                                  java.util.Collection userCandidates,
                                  boolean subclasses)

Constructor.

Parameters:

om - Object Manager

candidateClass - The candidate

userCandidates - The users candidates

subclasses - Whether to include subclasses

Method Detail

newQueryStatement

public org.datanucleus.store.mapped.expression.QueryExpression newQueryStatement()

Create a new query to search for the candidate classes etc.

Specified by:

newQueryStatement in interface org.datanucleus.store.mapped.expression.Queryable

Returns:

The new QueryStatement.

newQueryStatement

public org.datanucleus.store.mapped.expression.QueryExpression newQueryStatement(java.lang.Class candidateClass,
                                                                                 org.datanucleus.store.mapped.DatastoreIdentifier candidateAlias)

Create a query to search for the candidateClass and subclasses if true

Specified by:

newQueryStatement in interface org.datanucleus.store.mapped.expression.Queryable

Parameters:

candidateClass - The candidate

candidateAlias - Alias for the candidate

Returns:

The new QueryStatement

setHasAggregatedExpressionsOnly

public void setHasAggregatedExpressionsOnly(boolean flag)

Convenience method to set if we know there are only aggregate expressions and so can ignore any checks on the result expressions. This is typically called where we haven't done a full compile of the result just scanning for aggregate keywords, allowing us to generate the QueryStatement correctly.

Parameters:

flag - Whether we just have aggregates

setResultExpressions

public void setResultExpressions(org.datanucleus.store.mapped.expression.ScalarExpression[] expressions)

Parameters:

expressions - The expressions to set.

getResultExpressions

public org.datanucleus.store.mapped.expression.ScalarExpression[] getResultExpressions()

Returns:

The expressions to project.

hasAggregatedExpressionsOnly

public boolean hasAggregatedExpressionsOnly()

Whether only aggregated expressions are returned

Returns:

Whether it has only aggregate expressions

newResultObjectFactory

public org.datanucleus.store.query.ResultObjectFactory newResultObjectFactory(org.datanucleus.store.mapped.expression.QueryExpression stmt,
                                                                              boolean ignoreCache,
                                                                              java.lang.Class resultClass,
                                                                              boolean useFetchPlan)

Specified by:

newResultObjectFactory in interface org.datanucleus.store.mapped.expression.Queryable

isEmpty

public boolean isEmpty()

Returns true if this collection contains no elements.

Specified by:

isEmpty in interface org.datanucleus.store.mapped.expression.Queryable

Returns:

true if this collection contains no elements.