ReadObjectQuery (EclipseLink 2.6.0, API Reference)

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

Nested Class Summary
- Nested classes/interfaces inherited from class org.eclipse.persistence.queries.DatabaseQuery
  DatabaseQuery.ParameterType

Field Summary

Fields
Modifier and Type	Field and Description
`protected java.lang.Object`	`selectionId` 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, aggregateQueries, batchFetchPolicy, cacheUsage, CheckCacheByExactPrimaryKey, CheckCacheByPrimaryKey, CheckCacheOnly, CheckCacheThenDatabase, concreteSubclassCalls, concreteSubclassJoinedMappingIndexes, concreteSubclassQueries, ConformResultsInUnitOfWork, defaultBuilder, distinctState, DoNotCheckCache, DONT_USE_DISTINCT, fetchGroup, fetchGroupName, inMemoryQueryIndirectionPolicy, isCachedExpressionQuery, isPrePrepared, isReadOnly, isReferenceClassLocked, isResultSetAccessOptimizedQuery, isResultSetAccessOptimizedQueryDefault, isResultSetOptimizedQuery, joinedAttributeManager, loadGroup, lockModeType, NONE, nonFetchJoinAttributeExpressions, OPTIMISTIC, OPTIMISTIC_FORCE_INCREMENT, orderByExpressions, partialAttributeExpressions, PESSIMISTIC_, PESSIMISTIC_FORCE_INCREMENT, PESSIMISTIC_READ, PESSIMISTIC_WRITE, READ, shouldExtendPessimisticLockScope, shouldIncludeData, shouldOuterJoinSubclasses, shouldUseDefaultFetchGroup, shouldUseSerializedObjectPolicy, shouldUseSerializedObjectPolicyDefault, UNCOMPUTED_DISTINCT, unionExpressions, USE_DISTINCT, UseDescriptorSetting, usesResultSetAccessOptimization, waitTimeout, WRITE

Fields inherited from class org.eclipse.persistence.queries.ObjectBuildingQuery
DEFAULT_LOCK_MODE, executionTime, isCacheCheckComplete, LOCK, LOCK_NOWAIT, LOCK_RESULT_PROPERTY, lockingClause, NO_LOCK, prefetchedCacheKeys, referenceClass, referenceClassName, requiresDeferredLocks, shouldBuildNullForNullPk, shouldRefreshIdentityMapResult, shouldRefreshRemoteIdentityMapResult, shouldRegisterResultsInUnitOfWork, shouldUseExclusiveConnection, wasDefaultLockMode

Fields inherited from class org.eclipse.persistence.queries.ReadQuery
fetchSize, firstResult, maxResults, maxRows, queryId, queryResultCachingPolicy, temporaryCachedQueryResults

Fields inherited from class org.eclipse.persistence.queries.DatabaseQuery
accessors, allowNativeSQLQuery, argumentFields, argumentParameterTypes, arguments, argumentTypeNames, argumentTypes, argumentValues, BATCH_FETCH_PROPERTY, CascadeAggregateDelete, CascadeAllParts, CascadeByMapping, CascadeDependentParts, cascadePolicy, CascadePrivateParts, descriptor, descriptors, doNotRedirect, executionSession, flushOnExecute, hintString, isCustomQueryUsed, isExecutionClone, isNativeConnectionRequired, isPrepared, isUserDefined, isUserDefinedSQLCall, monitorName, name, NoCascading, nullableArguments, parameterDelimiter, partitioningPolicy, properties, queryMechanism, queryTimeout, redirector, session, sessionName, shouldBindAllParameters, shouldCacheStatement, shouldCloneCall, shouldMaintainCache, shouldPrepare, shouldRetrieveBypassCache, shouldStoreBypassCache, shouldUseWrapperPolicy, shouldValidateUpdateCallCacheUse, sourceMapping, translationRow

Constructor Summary

Constructors
Constructor and Description
`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

Methods
Modifier and Type	Method and Description
`void`	`cacheResult(java.lang.Object object)` 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`	`checkEarlyReturnLocal(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.
`void`	`clearSelectionId()` INTERNAL: Clear the selection id and object.
`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.
`protected java.lang.Object`	`getQueryPrimaryKey()` INTERNAL: Return the primary key stored in this query
`java.lang.Object`	`getSelectionId()` PUBLIC: Return Id of the object to be selected by the query.
`java.util.Vector`	`getSelectionKey()` Deprecated. since EclipseLink 2.1, replaced by getSelectionId()
`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 including 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`	`setSelectionId(java.lang.Object id)` PUBLIC: The Id of the object to be selected by the query.
`void`	`setSelectionKey(java.util.List selectionKey)` Deprecated. since EclipseLink 2.1, replaced by setSelectionId(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)` Deprecated. since EclipseLink 2.1, replaced by setSelectionId(Object)
`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, addBatchReadAttribute, addBatchReadAttribute, addDescendingOrdering, addJoinedAttribute, addJoinedAttribute, addJoinSelectionFields, addNonFetchJoin, addNonFetchJoinedAttribute, addNonFetchJoinedAttribute, addOrdering, addPartialAttribute, addPartialAttribute, addSelectionFieldsForJoinedExpression, addUnionExpression, buildObject, changeDescriptor, checkCacheOnly, checkEarlyReturn, checkPrepare, checkPrePrepare, clearIsResultSetOptimizedQuery, clearUsesResultSetAccessOptimization, clone, computeBatchReadAttributes, computeBatchReadMappingQueries, computeNestedQueriesForBatchReadExpressions, conformIndividualResult, conformResultsInUnitOfWork, deepClone, dontAcquireLocks, dontCheckCache, dontRefreshIdentityMapResult, dontRefreshRemoteIdentityMapResult, dontUseDistinct, equals, except, executeDatabaseQuery, executeInUnitOfWork, extendPessimisticLockScope, getAdditionalFields, getAggregateQueries, getAggregateQuery, getAsOfClause, getBatchFetchPolicy, getBatchObjects, getBatchReadAttributeExpressions, getCacheUsage, getConcreteSubclassCalls, getConcreteSubclassJoinedMappingIndexes, getConcreteSubclassQueries, getDistinctState, getExampleObject, getExecutionFetchGroup, getExecutionFetchGroup, getExpressionBuilder, getFetchGroup, getFetchGroupName, getFetchGroupNonNestedFieldsSet, getFetchGroupNonNestedFieldsSet, getFetchGroupSelectionFields, getFetchGroupSelectionFields, getInMemoryQueryIndirectionPolicy, getInMemoryQueryIndirectionPolicyState, getJoinedAttributeExpressions, getJoinedAttributeManager, getLoadGroup, getLockingClause, getLockModeType, getNonFetchJoinAttributeExpressions, getOrderByExpressions, getPartialAttributeExpressions, getPartialAttributeSelectionFields, getQueryByExamplePolicy, getReferenceClass, getReferenceClassName, getSelectionFields, getUnionExpressions, getWaitTimeout, hasAdditionalFields, hasAsOfClause, hasBatchReadAttributes, hasDefaultBuilder, hasExecutionFetchGroup, hasFetchGroup, hashCode, hasJoining, hasNonFetchJoinedAttributeExpressions, hasOrderByExpressions, hasPartialAttributeExpressions, hasUnionExpressions, initializeDefaultBuilder, intersect, isAttributeBatchRead, isCachedExpressionQuery, isClonePessimisticLocked, isDefaultLock, isDefaultPropertiesQuery, isDistinctComputed, isLockQuery, isLockQuery, isObjectLevelReadQuery, isPartialAttribute, isPrePrepared, isReadOnly, isReferenceClassLocked, isResultSetAccessOptimizedQuery, isResultSetOptimizedQuery, prepareFetchGroup, prepareForRemoteExecution, prepareFromCachedQuery, prepareFromQuery, prepareOutsideUnitOfWork, prepareQuery, prepareResultSetAccessOptimization, recordCloneForPessimisticLocking, refreshIdentityMapResult, refreshRemoteIdentityMapResult, resetDistinct, setAdditionalFields, setAggregateQuery, setAsOfClause, setBatchFetchPolicy, setBatchFetchSize, setBatchFetchType, setBatchObjects, setBatchReadAttributeExpressions, setCacheUsage, setDescriptor, setDistinctState, setEJBQLString, setExampleObject, setExpressionBuilder, setFetchGroup, setFetchGroupName, setInMemoryQueryIndirectionPolicy, setInMemoryQueryIndirectionPolicyState, setIsPrepared, setIsPreparedKeepingSubclassData, setIsPrePrepared, setIsReadOnly, setIsResultSetAccessOptimizedQuery, setIsResultSetOptimizedQuery, setJoinedAttributeExpressions, setJoinedAttributeManager, setLoadGroup, setLockingClause, setLockMode, setLockModeType, setNonFetchJoinAttributeExpressions, setOrderByExpressions, setPartialAttributeExpressions, setQueryByExamplePolicy, setReferenceClass, setReferenceClassName, setSelectionCriteria, setShouldExtendPessimisticLockScope, setShouldFilterDuplicates, setShouldIncludeData, setShouldOuterJoinSubclasses, setShouldUseDefaultFetchGroup, setShouldUseSerializedObjectPolicy, setUnionExpressions, setWaitTimeout, shouldCheckCache, shouldCheckCacheOnly, shouldCheckDescriptorForCacheUsage, shouldConformResultsInUnitOfWork, shouldDistinctBeUsed, shouldExtendPessimisticLockScope, shouldFilterDuplicates, shouldIncludeData, shouldOuterJoinSubclasses, shouldReadAllMappings, shouldReadMapping, shouldUseDefaultFetchGroup, shouldUseSerializedObjectPolicy, supportsResultSetAccessOptimizationOnExecute, supportsResultSetAccessOptimizationOnPrepare, toString, union, useDistinct, usesResultSetAccessOptimization

Methods inherited from class org.eclipse.persistence.queries.ReadQuery
cacheQueryResults, clearQueryResults, doNotCacheQueryResults, getFetchSize, getFirstResult, getInternalMax, getMaxRows, getQueryId, getQueryResults, getQueryResults, getQueryResults, getQueryResultsCachePolicy, getTemporaryCachedQueryResults, isReadQuery, remoteExecute, setFetchSize, setFirstResult, setInternalMax, setMaxRows, setQueryId, setQueryResults, setQueryResultsCachePolicy, setTemporaryCachedQueryResults, shouldCacheQueryResults

Methods inherited from class org.eclipse.persistence.queries.DatabaseQuery
addArgument, addArgument, addArgument, addArgument, addArgument, addArgument, addArgumentByTypeName, addArgumentValue, addArgumentValues, addCall, addStatement, bindAllParameters, buildArgumentFields, buildSelectionCriteria, cacheStatement, cascadeAllParts, cascadeByMapping, cascadeOnlyDependentParts, cascadePrivateParts, checkPrepare, dontBindAllParameters, dontCacheStatement, dontCascadeParts, dontMaintainCache, getAccessor, getAccessors, getArgumentParameterTypes, getArguments, getArgumentTypeNames, getArgumentTypes, getArgumentValues, getCall, getCascadePolicy, getDatasourceCall, getDatasourceCalls, getDescriptor, getDescriptors, getDomainClassNounName, getDoNotRedirect, getEJBQLString, getExecutionSession, getFlushOnExecute, getHintString, getJPQLString, getMonitorName, getName, getNullableArguments, getParameterDelimiter, getParameterDelimiterChar, getPartitioningPolicy, getProperties, getProperty, getQueryMechanism, getQueryNounName, getQueryTimeout, getRedirector, getRedirectorForQuery, getSelectionCriteria, getSensorName, getSession, getSessionName, getShouldBindAllParameters, getSourceMapping, getSQLStatement, getSQLString, getSQLStrings, getTranslatedSQLString, getTranslatedSQLStrings, getTranslationRow, hasAccessor, hasArguments, hasNullableArguments, 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, isResultSetMappingQuery, isSQLCallQuery, isUpdateAllQuery, isUpdateObjectQuery, isUserDefined, isUserDefinedSQLCall, isValueReadQuery, isWriteObjectQuery, maintainCache, prepareCall, prepareInternal, redirectQuery, removeProperty, resetMonitorName, retrieveBypassCache, rowFromArguments, setAccessor, setAccessors, setAllowNativeSQLQuery, setArguments, setArgumentTypeNames, setArgumentTypes, setArgumentValues, setCall, setCascadePolicy, setDatasourceCall, setDoNotRedirect, setExecutionSession, setFlushOnExecute, setHintString, setIsCustomQueryUsed, setIsExecutionClone, setIsNativeConnectionRequired, setIsUserDefined, setIsUserDefinedSQLCall, setJPQLString, setName, setNullableArguments, setParameterDelimiter, setPartitioningPolicy, setProperties, setProperty, setQueryMechanism, setQueryTimeout, setRedirector, setSession, setSessionName, setShouldBindAllParameters, setShouldBindAllParameters, setShouldCacheStatement, setShouldMaintainCache, setShouldPrepare, setShouldRetrieveBypassCache, setShouldStoreBypassCache, setShouldUseWrapperPolicy, setShouldValidateUpdateCallCacheUse, setSourceMapping, setSQLStatement, setSQLString, setTranslationRow, shouldAllowNativeSQLQuery, shouldBindAllParameters, shouldCacheStatement, shouldCascadeAllParts, shouldCascadeByMapping, shouldCascadeOnlyDependentParts, shouldCascadeParts, shouldCascadePrivateParts, shouldCloneCall, shouldIgnoreBindAllParameters, shouldIgnoreCacheStatement, shouldMaintainCache, shouldPrepare, shouldPrepare, shouldRetrieveBypassCache, shouldStoreBypassCache, shouldUseWrapperPolicy, shouldValidateUpdateCallCacheUse, storeBypassCache

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.
  - selectionId
```
protected java.lang.Object selectionId
```
    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 object)
```
    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
  - checkEarlyReturnLocal
```
protected java.lang.Object checkEarlyReturnLocal(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:
    
    checkEarlyReturnLocal 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
```
@Deprecated
public java.util.Vector getSelectionKey()
```
    Deprecated. since EclipseLink 2.1, replaced by getSelectionId()
    
    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.
    
    See Also:
    getSelectionId()
  - 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 including the translation row. This is used only for primary key queries, as the descriptor query manager stores a predefined query for this query to avoid having to re-prepare and allow for customization.
    
    Overrides:
    
    prepareCustomQuery in class ObjectBuildingQuery
  - 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
  - getQueryPrimaryKey
```
protected java.lang.Object getQueryPrimaryKey()
```
    INTERNAL: Return the primary key stored in this query
    
    Overrides:
    
    getQueryPrimaryKey in class ObjectBuildingQuery
    
    Returns:
    the selection id of this ReadObjectQuery
    See Also:
    ReadObjectQuery
  - getSelectionId
```
public java.lang.Object getSelectionId()
```
    PUBLIC: Return Id of the object to be selected by the query.
  - clearSelectionId
```
public void clearSelectionId()
```
    INTERNAL: Clear the selection id and object. This is done after cloning queries to prepare them in inheritance.
  - setSelectionId
```
public void setSelectionId(java.lang.Object id)
```
    PUBLIC: The Id of the object to be selected by the query. This will generate a query by primary key. This can be used instead of an Expression, SQL, or JPQL, or example object. The Id is the Id value for a singleton primary key, for a composite it is an instance of CacheId.
    
    See Also:
    CacheId
  - setSelectionKey
```
@Deprecated
public void setSelectionKey(java.util.List selectionKey)
```
    Deprecated. since EclipseLink 2.1, replaced by setSelectionId(Object)
    
    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.
    
    See Also:
    setSelectionId(Object)
  - 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
```
@Deprecated
public void setSingletonSelectionKey(java.lang.Object selectionKey)
```
    Deprecated. since EclipseLink 2.1, replaced by setSelectionId(Object)
    
    PUBLIC: The primary key can be specified if used instead of an expression or selection object.
    
    See Also:
    setSelectionId(Object)
  - 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.

Class ReadObjectQuery

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.persistence.queries.DatabaseQuery

Field Summary

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

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

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

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

Constructor Summary

Method Summary

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

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

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

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

Methods inherited from class java.lang.Object

Field Detail

selectionObject

selectionId

shouldLoadResultIntoSelectionObject

Constructor Detail

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

ReadObjectQuery

Method Detail

cacheResult

checkCacheByExactPrimaryKey

checkCacheByPrimaryKey

checkCacheThenDatabase

checkDescriptor

checkEarlyReturnLocal

checkForCustomQuery

conformResult

dontLoadResultIntoSelectionObject

execute

executeObjectLevelReadQuery

executeObjectLevelReadQueryFromResultSet

extractRemoteResult

getDefaultRedirector

getSelectionKey

getSelectionObject

isReadObjectQuery

isPrimaryKeyQuery

loadResultIntoSelectionObject

copyFromQuery

prepare

prepareCustomQuery

prepareForExecution

prePrepare

registerResultInUnitOfWork

remoteExecute

replaceValueHoldersIn

getQueryPrimaryKey

getSelectionId

clearSelectionId

setSelectionId

setSelectionKey

setSelectionObject

setShouldLoadResultIntoSelectionObject

setSingletonSelectionKey

shouldCheckCacheByExactPrimaryKey

shouldCheckCacheByPrimaryKey

shouldCheckCacheThenDatabase

shouldLoadResultIntoSelectionObject

hasNonDefaultFetchGroup