org.eclipse.persistence.queries
Class ReadObjectQuery

java.lang.Object
  org.eclipse.persistence.queries.DatabaseQuery
      org.eclipse.persistence.queries.ReadQuery
          org.eclipse.persistence.queries.ObjectBuildingQuery
              org.eclipse.persistence.queries.ObjectLevelReadQuery
                  org.eclipse.persistence.queries.ReadObjectQuery

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class ReadObjectQuery
extends ObjectLevelReadQuery

Purpose: Concrete class for all read queries involving a single object.

Responsibilities: Return a single object for the query. Implements the inheritance feature when dealing with abstract descriptors.

See Also:

Serialized Form

Author:

Yvon Lavoie

Since:

TOPLink/Java 1.0

Field Summary

protected java.util.Vector	selectionKey Key that can be used in place of a selection criteria.
protected java.lang.Object	selectionObject Object that can be used in place of a selection criteria.
protected boolean	shouldLoadResultIntoSelectionObject Can be used to refresh a specific non-cached instance from the database.

Fields inherited from class org.eclipse.persistence.queries.ObjectLevelReadQuery

additionalFields, cacheUsage, CheckCacheByExactPrimaryKey, CheckCacheByPrimaryKey, CheckCacheOnly, CheckCacheThenDatabase, concreteSubclassCalls, ConformResultsInUnitOfWork, defaultBuilder, distinctState, DoNotCheckCache, DONT_USE_DISTINCT, executionTime, fetchGroup, fetchGroupName, inMemoryQueryIndirectionPolicy, isPrePrepared, isReadOnly, isReferenceClassLocked, isResultSetOptimizedQuery, joinedAttributeManager, lockModeType, NONE, nonFetchJoinAttributeExpressions, OPTIMISTIC, OPTIMISTIC_FORCE_INCREMENT, orderByExpressions, partialAttributeExpressions, PESSIMISTIC_, PESSIMISTIC_FORCE_INCREMENT, PESSIMISTIC_READ, PESSIMISTIC_WRITE, READ, shouldExtendPessimisticLockScope, shouldIncludeData, shouldOuterJoinSubclasses, shouldUseDefaultFetchGroup, UNCOMPUTED_DISTINCT, USE_DISTINCT, UseDescriptorSetting, waitTimeout, WRITE

Fields inherited from class org.eclipse.persistence.queries.ObjectBuildingQuery

DEFAULT_LOCK_MODE, LOCK, LOCK_NOWAIT, LOCK_RESULT_PROPERTY, lockingClause, NO_LOCK, referenceClass, referenceClassName, shouldBuildNullForNullPk, shouldProcessResultsInUnitOfWork, shouldRefreshIdentityMapResult, shouldRefreshRemoteIdentityMapResult, shouldRegisterResultsInUnitOfWork, shouldUseExclusiveConnection, wasDefaultLockMode

Fields inherited from class org.eclipse.persistence.queries.ReadQuery

fetchSize, firstResult, maxRows, queryId, queryResultCachingPolicy, temporaryCachedQueryResults

Fields inherited from class org.eclipse.persistence.queries.DatabaseQuery

accessor, argumentFields, arguments, argumentTypeNames, argumentTypes, argumentValues, CascadeAggregateDelete, CascadeAllParts, CascadeByMapping, CascadeDependentParts, cascadePolicy, CascadePrivateParts, descriptor, doNotRedirect, executionSession, flushOnExecute, hintString, isCustomQueryUsed, isExecutionClone, isNativeConnectionRequired, isPrepared, isUserDefined, name, NoCascading, properties, queryMechanism, queryTimeout, redirector, session, sessionName, shouldBindAllParameters, shouldCacheStatement, shouldCloneCall, shouldMaintainCache, shouldPrepare, shouldRetrieveBypassCache, shouldStoreBypassCache, shouldUseWrapperPolicy, sourceMapping, translationRow

Constructor Summary

ReadObjectQuery()
PUBLIC: Return a new read object query.

ReadObjectQuery(Call call)
PUBLIC: Return a new read object query.

ReadObjectQuery(java.lang.Class classToRead)
PUBLIC: Return a new read object query.

ReadObjectQuery(java.lang.Class classToRead, Call call)
PUBLIC: Return a new read object query.

ReadObjectQuery(java.lang.Class classToRead, Expression selectionCriteria)
PUBLIC: Return a new read object query for the class and the selection criteria.

ReadObjectQuery(java.lang.Class classToRead, ExpressionBuilder builder)
PUBLIC: Return a new read object query for the class.

ReadObjectQuery(ExpressionBuilder builder)
PUBLIC: The expression builder should be provide on creation to ensure only one is used.

ReadObjectQuery(java.lang.Object objectToRead)
PUBLIC: Return a query to read the object with the same primary key as the provided object.

ReadObjectQuery(java.lang.Object exampleObject, QueryByExamplePolicy policy)
PUBLIC: Return a query by example query to find an object matching the attributes of the example object.

Method Summary

void	cacheResult(java.lang.Object unwrappedOriginal) INTERNAL: This method is called by the object builder when building an original.
void	checkCacheByExactPrimaryKey() PUBLIC: The cache will be checked only if the query contains exactly the primary key.
void	checkCacheByPrimaryKey() PUBLIC: This is the default, the cache will be checked only if the query contains the primary key.
void	checkCacheThenDatabase() PUBLIC: The cache will be checked completely, then if the object is not found or the query too complex the database will be queried.
void	checkDescriptor(org.eclipse.persistence.internal.sessions.AbstractSession session) INTERNAL: Ensure that the descriptor has been set.
protected java.lang.Object	checkEarlyReturnImpl(org.eclipse.persistence.internal.sessions.AbstractSession session, org.eclipse.persistence.internal.sessions.AbstractRecord translationRow) INTERNAL: The cache check is done before the prepare as a hit will not require the work to be done.
protected DatabaseQuery	checkForCustomQuery(org.eclipse.persistence.internal.sessions.AbstractSession session, org.eclipse.persistence.internal.sessions.AbstractRecord translationRow) INTERNAL: Check to see if a custom query should be used for this query.
protected java.lang.Object	conformResult(java.lang.Object result, org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork, org.eclipse.persistence.internal.sessions.AbstractRecord databaseRow, boolean buildDirectlyFromRows) INTERNAL: Conform the result in the UnitOfWork.
void	copyFromQuery(DatabaseQuery query) INTERNAL: Copy all setting from the query.
void	dontLoadResultIntoSelectionObject() PUBLIC: Do not refesh/load into the selection object, this is the default.
java.lang.Object	execute(org.eclipse.persistence.internal.sessions.AbstractSession session, org.eclipse.persistence.internal.sessions.AbstractRecord row) INTERNAL: Execute the query.
protected java.lang.Object	executeObjectLevelReadQuery() INTERNAL: Execute the query.
protected java.lang.Object	executeObjectLevelReadQueryFromResultSet() INTERNAL: Execute the query building the objects directly from the database result-set.
java.lang.Object	extractRemoteResult(org.eclipse.persistence.internal.sessions.remote.Transporter transporter) INTERNAL: Extract the correct query result from the transporter.
protected QueryRedirector	getDefaultRedirector() INTERNAL: Returns the specific default redirector for this query type.
java.util.Vector	getSelectionKey() PUBLIC: The primary key can be specified if used instead of an expression or selection object.
java.lang.Object	getSelectionObject() PUBLIC: Return the selection object of the query.
protected boolean	hasNonDefaultFetchGroup() INTERNAL: Return if the query has an non-default fetch group defined for itself.
boolean	isPrimaryKeyQuery() INTERNAL: Return if the query is by primary key.
boolean	isReadObjectQuery() PUBLIC: Return if this is a read object query.
void	loadResultIntoSelectionObject() PUBLIC: Allow for the selection object of the query to be refreshed or put into the EclipseLink cache.
protected void	prepare() INTERNAL: Prepare the receiver for execution in a session.
protected void	prepareCustomQuery(DatabaseQuery customQuery) INTERNAL: Set the properties needed to be cascaded into the custom query inlucding the translation row.
void	prepareForExecution() INTERNAL: Prepare the receiver for execution in a session.
protected void	prePrepare() INTERNAL: Prepare the receiver for execution in a session.
java.lang.Object	registerResultInUnitOfWork(java.lang.Object result, org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork, org.eclipse.persistence.internal.sessions.AbstractRecord arguments, boolean buildDirectlyFromRows) INTERNAL: All objects queried via a UnitOfWork get registered here.
protected java.lang.Object	remoteExecute()
java.util.Map	replaceValueHoldersIn(java.lang.Object object, org.eclipse.persistence.internal.sessions.remote.RemoteSessionController controller) INTERNAL: replace the value holders in the specified result object(s)
void	setSelectionKey(java.util.List selectionKey) PUBLIC: The primary key can be specified if used instead of an expression or selection object.
void	setSelectionObject(java.lang.Object selectionObject) PUBLIC: Used to set the where clause of the query.
void	setShouldLoadResultIntoSelectionObject(boolean shouldLoadResultIntoSelectionObject) PUBLIC: Allow for the selection object of the query to be refreshed or put into the EclipseLink cache.
void	setSingletonSelectionKey(java.lang.Object selectionKey) PUBLIC: The primary key can be specified if used instead of an expression or selection object.
boolean	shouldCheckCache() PUBLIC: Return if the cache should be checked.
boolean	shouldCheckCacheByExactPrimaryKey() PUBLIC: Return if cache should be checked.
boolean	shouldCheckCacheByPrimaryKey() PUBLIC: Return if cache should be checked.
boolean	shouldCheckCacheThenDatabase() PUBLIC: Return if cache should be checked.
boolean	shouldLoadResultIntoSelectionObject() PUBLIC: return true if the result should be loaded into the passed in selection Object

Methods inherited from class org.eclipse.persistence.queries.ObjectLevelReadQuery

acquireLocks, acquireLocksWithoutWaiting, addAdditionalField, addAdditionalField, addDescendingOrdering, addJoinedAttribute, addJoinedAttribute, addNonFetchJoinedAttribute, addNonFetchJoinedAttribute, addOrdering, addPartialAttribute, addPartialAttribute, addSelectionFieldsForJoinedExpressions, buildObject, changeDescriptor, checkCacheOnly, checkEarlyReturn, checkPrepare, checkPrePrepare, clone, conformIndividualResult, conformResultsInUnitOfWork, deepClone, dontAcquireLocks, dontCheckCache, dontRefreshIdentityMapResult, dontRefreshRemoteIdentityMapResult, dontUseDistinct, equals, executeDatabaseQuery, executeInUnitOfWork, extendPessimisticLockScope, getAdditionalFields, getAsOfClause, getCacheUsage, getConcreteSubclassCalls, getDistinctState, getExampleObject, getExecutionTime, getExpressionBuilder, getFetchGroup, getFetchGroupName, getFetchGroupSelectionFields, getInMemoryQueryIndirectionPolicy, getInMemoryQueryIndirectionPolicyState, getJoinedAttributeExpressions, getJoinedAttributeManager, getLeafDescriptorFor, getLeafMappingFor, getLockingClause, getLockMode, getNonFetchJoinAttributeExpressions, getOrderByExpressions, getPartialAttributeExpressions, getPartialAttributeSelectionFields, getQueryByExamplePolicy, getReferenceClass, getReferenceClassName, getSelectionFields, getWaitTimeout, hasAdditionalFields, hasAsOfClause, hasFetchGroup, hashCode, hasJoining, hasNonFetchJoinedAttributeExpressions, hasOrderByExpressions, hasPartialAttributeExpressions, initializeDefaultBuilder, initializeFetchGroup, isClonePessimisticLocked, isDefaultLock, isDefaultPropertiesQuery, isDistinctComputed, isFetchGroupAttribute, isLockQuery, isLockQuery, isObjectLevelReadQuery, isPartialAttribute, isPrePrepared, isReadOnly, isReferenceClassLocked, isRegisteringResults, isResultSetOptimizedQuery, prepareForRemoteExecution, prepareFromCachedQuery, prepareFromQuery, prepareOutsideUnitOfWork, prepareQuery, recordCloneForPessimisticLocking, refreshIdentityMapResult, refreshRemoteIdentityMapResult, resetDistinct, setAdditionalFields, setAsOfClause, setCacheUsage, setDescriptor, setDistinctState, setEJBQLString, setExampleObject, setExecutionTime, setExpressionBuilder, setFetchGroup, setFetchGroupName, setInMemoryQueryIndirectionPolicy, setInMemoryQueryIndirectionPolicyState, setIsPrepared, setIsPrePrepared, setIsReadOnly, setIsResultSetOptimizedQuery, setJoinedAttributeExpressions, setJoinedAttributeManager, setLockingClause, setLockMode, setLockModeType, setNonFetchJoinAttributeExpressions, setOrderByExpressions, setPartialAttributeExpressions, setQueryByExamplePolicy, setReferenceClass, setReferenceClassName, setSelectionCriteria, setShouldExtendPessimisticLockScope, setShouldFilterDuplicates, setShouldIncludeData, setShouldOuterJoinSubclasses, setShouldProcessResultsInUnitOfWork, setShouldRefreshIdentityMapResult, setShouldRefreshRemoteIdentityMapResult, setShouldRegisterResultsInUnitOfWork, setShouldUseDefaultFetchGroup, setWaitTimeout, setWasDefaultLockMode, shouldCheckCacheOnly, shouldCheckDescriptorForCacheUsage, shouldConformResultsInUnitOfWork, shouldDistinctBeUsed, shouldExtendPessimisticLockScope, shouldFilterDuplicates, shouldIncludeData, shouldOuterJoinSubclasses, shouldProcessResultsInUnitOfWork, shouldReadAllMappings, shouldReadMapping, shouldRefreshIdentityMapResult, shouldRefreshRemoteIdentityMapResult, shouldRegisterResultsInUnitOfWork, shouldUseDefaultFetchGroup, useDistinct, wasDefaultLockMode

Methods inherited from class org.eclipse.persistence.queries.ObjectBuildingQuery

convertClassNamesToClasses, getDataResults, isAttributeJoined, isObjectBuildingQuery, registerIndividualResult, setShouldBuildNullForNullPk, setShouldUseExclusiveConnection, shouldBuildNullForNullPk, shouldUseExclusiveConnection

Methods inherited from class org.eclipse.persistence.queries.ReadQuery

cacheQueryResults, clearQueryResults, clonedQueryExecutionComplete, doNotCacheQueryResults, getFetchSize, getFirstResult, getMaxRows, getQueryId, getQueryResults, getQueryResults, getQueryResults, getQueryResultsCachePolicy, getTemporaryCachedQueryResults, isReadQuery, remoteExecute, setFetchSize, setFirstResult, setMaxRows, setQueryId, setQueryResults, setQueryResultsCachePolicy, setTemporaryCachedQueryResults, shouldCacheQueryResults

Methods inherited from class org.eclipse.persistence.queries.DatabaseQuery

addArgument, addArgument, addArgument, addArgumentByTypeName, addArgumentValue, addArgumentValues, addCall, addStatement, bindAllParameters, buildArgumentFields, buildSelectionCriteria, cacheStatement, cascadeAllParts, cascadeByMapping, cascadeOnlyDependentParts, cascadePrivateParts, checkPrepare, dontBindAllParameters, dontCacheStatement, dontCascadeParts, dontMaintainCache, getAccessor, getArguments, getArgumentTypeNames, getArgumentTypes, getArgumentValues, getCall, getCascadePolicy, getDatasourceCall, getDatasourceCalls, getDescriptor, getDomainClassNounName, getDoNotRedirect, getEJBQLString, getExecutionSession, getFlushOnExecute, getHintString, getJPQLString, getName, getProperties, getProperty, getQueryMechanism, getQueryNounName, getQueryTimeout, getRedirector, getSelectionCriteria, getSensorName, getSession, getSessionName, getShouldBindAllParameters, getSourceMapping, getSQLStatement, getSQLString, getSQLStrings, getTranslatedSQLString, getTranslatedSQLStrings, getTranslationRow, hasAccessor, hasArguments, hasProperties, hasQueryMechanism, hasSessionName, ignoreBindAllParameters, ignoreCacheStatement, isCallQuery, isCascadeOfAggregateDelete, isCustomQueryUsed, isCustomSelectionQuery, isDataModifyQuery, isDataReadQuery, isDeleteAllQuery, isDeleteObjectQuery, isDirectReadQuery, isExecutionClone, isExpressionQuery, isInsertObjectQuery, isJPQLCallQuery, isModifyAllQuery, isModifyQuery, isNativeConnectionRequired, isObjectLevelModifyQuery, isPrepared, isReadAllQuery, isReportQuery, isSQLCallQuery, isUpdateAllQuery, isUpdateObjectQuery, isUserDefined, isValueReadQuery, isWriteObjectQuery, maintainCache, prepareCall, redirectQuery, removeProperty, retrieveBypassCache, rowFromArguments, setAccessor, setArguments, setArgumentTypeNames, setArgumentTypes, setArgumentValues, setCall, setCascadePolicy, setDatasourceCall, setDoNotRedirect, setExecutionSession, setFlushOnExecute, setHintString, setIsCustomQueryUsed, setIsExecutionClone, setIsNativeConnectionRequired, setIsUserDefined, setJPQLString, setName, setProperties, setProperty, setQueryMechanism, setQueryTimeout, setRedirector, setSession, setSessionName, setShouldBindAllParameters, setShouldBindAllParameters, setShouldCacheStatement, setShouldMaintainCache, setShouldPrepare, setShouldRetrieveBypassCache, setShouldStoreBypassCache, setShouldUseWrapperPolicy, setSourceMapping, setSQLStatement, setSQLString, setTranslationRow, shouldBindAllParameters, shouldCacheStatement, shouldCascadeAllParts, shouldCascadeByMapping, shouldCascadeOnlyDependentParts, shouldCascadeParts, shouldCascadePrivateParts, shouldCloneCall, shouldIgnoreBindAllParameters, shouldIgnoreCacheStatement, shouldMaintainCache, shouldPrepare, shouldRetrieveBypassCache, shouldStoreBypassCache, shouldUseWrapperPolicy, storeBypassCache, toString

Methods inherited from class java.lang.Object

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

Field Detail

selectionObject

protected transient java.lang.Object selectionObject

Object that can be used in place of a selection criteria.

selectionKey

protected java.util.Vector selectionKey

Key that can be used in place of a selection criteria.

shouldLoadResultIntoSelectionObject

protected boolean shouldLoadResultIntoSelectionObject

Can be used to refresh a specific non-cached instance from the database.

Constructor Detail

ReadObjectQuery

public ReadObjectQuery()

PUBLIC: Return a new read object query. A reference class must be specified before execution. It is better to provide the class and expression builder on construction to esnure a single expression builder is used. If no selection criteria is specified this will reads the first object found in the database.

ReadObjectQuery

public ReadObjectQuery(java.lang.Class classToRead)

PUBLIC: Return a new read object query. By default, the query has no selection criteria. Executing this query without selection criteria will always result in a database access to read the first instance of the specified Class found in the database. This is true no matter how cache usage is configured and even if an instance of the specified Class exists in the cache. Executing a query with selection criteria allows you to avoid a database access if the selected instance is in the cache. For this reason, you may whish to use a ReadObjectQuery constructor that takes selection criteria, such as: ReadObjectQuery(Class, Call), ReadObjectQuery(Class, Expression), ReadObjectQuery(Class, ExpressionBuilder), ReadObjectQuery(ExpressionBuilder), ReadObjectQuery(Object), or ReadObjectQuery(Object, QueryByExamplePolicy).

ReadObjectQuery

public ReadObjectQuery(java.lang.Class classToRead,
                       Expression selectionCriteria)

PUBLIC: Return a new read object query for the class and the selection criteria.

ReadObjectQuery

public ReadObjectQuery(java.lang.Class classToRead,
                       ExpressionBuilder builder)

PUBLIC: Return a new read object query for the class. The expression builder must be used for all associated expressions used with the query.

ReadObjectQuery

public ReadObjectQuery(java.lang.Class classToRead,
                       Call call)

PUBLIC: Return a new read object query. The call represents a database interaction such as SQL, Stored Procedure.

ReadObjectQuery

public ReadObjectQuery(Call call)

PUBLIC: Return a new read object query. The call represents a database interaction such as SQL, Stored Procedure.

ReadObjectQuery

public ReadObjectQuery(java.lang.Object objectToRead)

PUBLIC: Return a query to read the object with the same primary key as the provided object. Note: This is not a query by example object, only the primary key will be used for the selection criteria.

ReadObjectQuery

public ReadObjectQuery(java.lang.Object exampleObject,
                       QueryByExamplePolicy policy)

PUBLIC: Return a query by example query to find an object matching the attributes of the example object.

ReadObjectQuery

public ReadObjectQuery(ExpressionBuilder builder)

PUBLIC: The expression builder should be provide on creation to ensure only one is used.

Method Detail

cacheResult

public void cacheResult(java.lang.Object unwrappedOriginal)

INTERNAL:

This method is called by the object builder when building an original. It will cause the original to be cached in the query results if the query is set to do so.

Specified by:

cacheResult in class ReadQuery

checkCacheByExactPrimaryKey

public void checkCacheByExactPrimaryKey()

PUBLIC: The cache will be checked only if the query contains exactly the primary key. Queries can be configured to use the cache at several levels. Other caching option are available.

See Also:

ObjectLevelReadQuery.setCacheUsage(int)

checkCacheByPrimaryKey

public void checkCacheByPrimaryKey()

PUBLIC: This is the default, the cache will be checked only if the query contains the primary key. Queries can be configured to use the cache at several levels. Other caching option are available.

See Also:

ObjectLevelReadQuery.setCacheUsage(int)

checkCacheThenDatabase

public void checkCacheThenDatabase()

PUBLIC: The cache will be checked completely, then if the object is not found or the query too complex the database will be queried. Queries can be configured to use the cache at several levels. Other caching option are available.

See Also:

ObjectLevelReadQuery.setCacheUsage(int)

checkDescriptor

public void checkDescriptor(org.eclipse.persistence.internal.sessions.AbstractSession session)
                     throws QueryException

INTERNAL: Ensure that the descriptor has been set.

Overrides:

checkDescriptor in class ObjectLevelReadQuery

Throws:

QueryException

checkEarlyReturnImpl

protected java.lang.Object checkEarlyReturnImpl(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                                org.eclipse.persistence.internal.sessions.AbstractRecord translationRow)

INTERNAL: The cache check is done before the prepare as a hit will not require the work to be done.

Specified by:

checkEarlyReturnImpl in class ObjectLevelReadQuery

checkForCustomQuery

protected DatabaseQuery checkForCustomQuery(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                            org.eclipse.persistence.internal.sessions.AbstractRecord translationRow)

INTERNAL: Check to see if a custom query should be used for this query. This is done before the query is copied and prepared/executed. null means there is none.

Overrides:

checkForCustomQuery in class DatabaseQuery

conformResult

protected java.lang.Object conformResult(java.lang.Object result,
                                         org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork,
                                         org.eclipse.persistence.internal.sessions.AbstractRecord databaseRow,
                                         boolean buildDirectlyFromRows)

INTERNAL: Conform the result in the UnitOfWork.

dontLoadResultIntoSelectionObject

public void dontLoadResultIntoSelectionObject()

PUBLIC: Do not refesh/load into the selection object, this is the default. This property allows for the selection object of the query to be refreshed or put into the TopLink cache. By default on a read or refresh the object in the cache is refreshed and returned or a new object is built from the database, in some cases such as EJB BMP it is desirable to refresh or load into the object passed into the read object query.

Note: This forces the selection object into the cache a replaces any existing object that may already be there, this is a strict violation of object identity and other objects can still be refering to the old object.

execute

public java.lang.Object execute(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                org.eclipse.persistence.internal.sessions.AbstractRecord row)
                         throws DatabaseException

INTERNAL: Execute the query. If there are cached results return those. This must override the super to support result caching.

Overrides:

execute in class ObjectLevelReadQuery

Parameters:

session - the session in which the receiver will be executed.

Returns:

An object or vector, the result of executing the query.

Throws:

DatabaseException - - an error has occurred on the database

executeObjectLevelReadQuery

protected java.lang.Object executeObjectLevelReadQuery()
                                                throws DatabaseException

INTERNAL: Execute the query. Do a cache lookup and build object from row if required.

Specified by:

executeObjectLevelReadQuery in class ObjectLevelReadQuery

Returns:

object - the first object found or null if none.

Throws:

DatabaseException - - an error has occurred on the database

executeObjectLevelReadQueryFromResultSet

protected java.lang.Object executeObjectLevelReadQueryFromResultSet()
                                                             throws DatabaseException

INTERNAL: Execute the query building the objects directly from the database result-set.

Specified by:

executeObjectLevelReadQueryFromResultSet in class ObjectLevelReadQuery

Returns:

object - the first object found or null if none.

Throws:

DatabaseException - - an error has occurred on the database

extractRemoteResult

public java.lang.Object extractRemoteResult(org.eclipse.persistence.internal.sessions.remote.Transporter transporter)

INTERNAL: Extract the correct query result from the transporter.

Overrides:

extractRemoteResult in class DatabaseQuery

getDefaultRedirector

protected QueryRedirector getDefaultRedirector()

INTERNAL: Returns the specific default redirector for this query type. There are numerous default query redirectors. See ClassDescriptor for their types.

Overrides:

getDefaultRedirector in class DatabaseQuery

getSelectionKey

public java.util.Vector getSelectionKey()

PUBLIC: The primary key can be specified if used instead of an expression or selection object. If composite the primary must be in the same order as defined in the descriptor.

getSelectionObject

public java.lang.Object getSelectionObject()

PUBLIC: Return the selection object of the query. This can be used instead of a where clause expression for single object primary key queries. The selection object given should have a primary key defined, this primary key will be used to query the database instance of the same object. This is a basic form of query by example where only the primary key is required, it can be used for simple query forms, or testing.

isReadObjectQuery

public boolean isReadObjectQuery()

PUBLIC: Return if this is a read object query.

Overrides:

isReadObjectQuery in class DatabaseQuery

isPrimaryKeyQuery

public boolean isPrimaryKeyQuery()

INTERNAL: Return if the query is by primary key.

Overrides:

isPrimaryKeyQuery in class ObjectLevelReadQuery

loadResultIntoSelectionObject

public void loadResultIntoSelectionObject()

PUBLIC: Allow for the selection object of the query to be refreshed or put into the EclipseLink cache. By default on a read or refresh the object in the cache is refreshed and returned or a new object is built from the database, in some cases such as EJB BMP it is desirable to refresh or load into the object passed into the read object query.

Note: This forces the selection object into the cache a replaces any existing object that may already be there, this is a strict violation of object identity and other objects can still be referring to the old object.

copyFromQuery

public void copyFromQuery(DatabaseQuery query)

INTERNAL: Copy all setting from the query. This is used to morph queries from one type to the other. By default this calls prepareFromQuery, but additional properties may be required to be copied as prepareFromQuery only copies properties that affect the SQL.

Overrides:

copyFromQuery in class ObjectLevelReadQuery

prepare

protected void prepare()
                throws QueryException

INTERNAL: Prepare the receiver for execution in a session.

Overrides:

prepare in class ObjectLevelReadQuery

Throws:

QueryException

prepareCustomQuery

protected void prepareCustomQuery(DatabaseQuery customQuery)

INTERNAL: Set the properties needed to be cascaded into the custom query inlucding the translation row.

Overrides:

prepareCustomQuery in class DatabaseQuery

prepareForExecution

public void prepareForExecution()
                         throws QueryException

INTERNAL: Prepare the receiver for execution in a session.

Overrides:

prepareForExecution in class ReadQuery

Throws:

QueryException

prePrepare

protected void prePrepare()
                   throws QueryException

INTERNAL: Prepare the receiver for execution in a session.

Overrides:

prePrepare in class ObjectLevelReadQuery

Throws:

QueryException

registerResultInUnitOfWork

public java.lang.Object registerResultInUnitOfWork(java.lang.Object result,
                                                   org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork,
                                                   org.eclipse.persistence.internal.sessions.AbstractRecord arguments,
                                                   boolean buildDirectlyFromRows)

INTERNAL: All objects queried via a UnitOfWork get registered here. If the query went to the database.

Involves registering the query result individually and in totality, and hence refreshing / conforming is done here.

Specified by:

registerResultInUnitOfWork in class ObjectLevelReadQuery

Parameters:

result - may be collection (read all) or an object (read one), or even a cursor. If in transaction the shared cache will be bypassed, meaning the result may not be originals from the parent but raw database rows.

unitOfWork - the unitOfWork the result is being registered in.

arguments - the original arguments/parameters passed to the query execution. Used by conforming

buildDirectlyFromRows - If in transaction must construct a registered result from raw database rows.

Returns:

the final (conformed, refreshed, wrapped) UnitOfWork query result

remoteExecute

protected java.lang.Object remoteExecute()

Overrides:

remoteExecute in class DatabaseQuery

replaceValueHoldersIn

public java.util.Map replaceValueHoldersIn(java.lang.Object object,
                                           org.eclipse.persistence.internal.sessions.remote.RemoteSessionController controller)

INTERNAL: replace the value holders in the specified result object(s)

Overrides:

replaceValueHoldersIn in class DatabaseQuery

setSelectionKey

public void setSelectionKey(java.util.List selectionKey)

PUBLIC: The primary key can be specified if used instead of an expression or selection object. If composite the primary must be in the same order as defined in the descriptor.

setSelectionObject

public void setSelectionObject(java.lang.Object selectionObject)

PUBLIC: Used to set the where clause of the query. This can be used instead of a where clause expression for single object primary key queries. The selection object given should have a primary key defined, this primary key will be used to query the database instance of the same object. This is a basic form of query by example where only the primary key is required, it can be used for simple query forms, or testing.

setShouldLoadResultIntoSelectionObject

public void setShouldLoadResultIntoSelectionObject(boolean shouldLoadResultIntoSelectionObject)

PUBLIC: Allow for the selection object of the query to be refreshed or put into the EclipseLink cache. By default on a read or refresh the object in the cache is refreshed and returned or a new object is built from the database, in some cases such as EJB BMP it is desirable to refresh or load into the object passed into the read object query.

Note: This forces the selection object into the cache a replaces any existing object that may already be there, this is a strict violation of object identity and other objects can still be referring to the old object.

setSingletonSelectionKey

public void setSingletonSelectionKey(java.lang.Object selectionKey)

PUBLIC: The primary key can be specified if used instead of an expression or selection object.

shouldCheckCache

public boolean shouldCheckCache()

PUBLIC: Return if the cache should be checked.

shouldCheckCacheByExactPrimaryKey

public boolean shouldCheckCacheByExactPrimaryKey()

PUBLIC: Return if cache should be checked.

shouldCheckCacheByPrimaryKey

public boolean shouldCheckCacheByPrimaryKey()

PUBLIC: Return if cache should be checked.

shouldCheckCacheThenDatabase

public boolean shouldCheckCacheThenDatabase()

PUBLIC: Return if cache should be checked.

shouldLoadResultIntoSelectionObject

public boolean shouldLoadResultIntoSelectionObject()

PUBLIC: return true if the result should be loaded into the passed in selection Object

hasNonDefaultFetchGroup

protected boolean hasNonDefaultFetchGroup()

INTERNAL: Return if the query has an non-default fetch group defined for itself.