org.apache.cayenne.query

Class SelectById<T>

java.lang.Object

org.apache.cayenne.query.IndirectQuery

org.apache.cayenne.query.SelectById<T>

All Implemented Interfaces:

Serializable, ConfigurationNode, Query, Select<T>

public class SelectById<T>
extends IndirectQuery
implements Select<T>

A query to select single objects by id.

Since:

4.0

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.cayenne.query.IndirectQuery

dataMap, lastResolver, name, replacementQuery

Constructor Summary

Constructors

Constructor and Description
SelectById()

Method Summary

Methods

Modifier and Type	Method and Description
SelectById<T>	addPrefetch(PrefetchTreeNode prefetch) Merges prefetch into the query prefetch tree.
SelectById<T>	addPrefetch(String path, int semantics) Merges a prefetch path with specified semantics into the query prefetch tree.
protected Query	createReplacementQuery(EntityResolver resolver) Creates a substitute query.
static SelectById<DataRow>	dataRowQuery(Class<?> entityType, Map<String,Object> id)
static SelectById<DataRow>	dataRowQuery(Class<?> entityType, Object id)
static SelectById<DataRow>	dataRowQuery(ObjectId id)
String[]	getCacheGroups()
QueryCacheStrategy	getCacheStrategy()
PrefetchTreeNode	getPrefetches()
boolean	isFetchingDataRows()
SelectById<T>	prefetch(PrefetchTreeNode prefetch) Resets internal prefetches to the new value.
SelectById<T>	prefetch(String path, int semantics) Resets internal prefetches to the new value, which is a single prefetch with specified semantics.
static <T> SelectById<T>	query(Class<T> entityType, Map<String,?> id)
static <T> SelectById<T>	query(Class<T> entityType, Object id)
static <T> SelectById<T>	query(Class<T> entityType, ObjectId id)
protected ObjEntity	resolveEntity(EntityResolver resolver)
protected Map<String,?>	resolveId(ObjEntity entity)
T	selectOne(ObjectContext context) Selects a single object using provided context.
SelectById<T>	useLocalCache(String... cacheGroups) Instructs Cayenne to look for query results in the "local" cache when running the query.
SelectById<T>	useSharedCache(String... cacheGroups)

Methods inherited from class org.apache.cayenne.query.IndirectQuery

acceptVisitor, createSQLAction, getDataMap, getMetaData, getName, getReplacementQuery, route, setDataMap, setName

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cayenne.query.Query

createSQLAction, getDataMap, getMetaData, getName, route

Methods inherited from interface org.apache.cayenne.configuration.ConfigurationNode

acceptVisitor

Constructor Detail

SelectById

public SelectById()

Method Detail

query

public static <T> SelectById<T> query(Class<T> entityType,
                      Object id)

query

public static <T> SelectById<T> query(Class<T> entityType,
                      Map<String,?> id)

query

public static <T> SelectById<T> query(Class<T> entityType,
                      ObjectId id)

dataRowQuery

public static SelectById<DataRow> dataRowQuery(Class<?> entityType,
                               Object id)

dataRowQuery

public static SelectById<DataRow> dataRowQuery(Class<?> entityType,
                               Map<String,Object> id)

dataRowQuery

public static SelectById<DataRow> dataRowQuery(ObjectId id)

selectOne

public T selectOne(ObjectContext context)

Selects a single object using provided context. The query is expected to match zero or one object. It returns null if no objects were matched. If query matched more than one object, CayenneRuntimeException is thrown. Since we are selecting by ID, multiple matched objects likely indicate a database referential integrity problem.

Essentially the inversion of "ObjectContext.selectOne(Select)".

useLocalCache

public SelectById<T> useLocalCache(String... cacheGroups)

Instructs Cayenne to look for query results in the "local" cache when running the query. This is a short-hand notation for:

 query.setCacheStrategy(QueryCacheStrategy.LOCAL_CACHE);
 query.setCacheGroups("group1", "group2");
 

Since:

4.0

useSharedCache

public SelectById<T> useSharedCache(String... cacheGroups)

getCacheStrategy

public QueryCacheStrategy getCacheStrategy()

getCacheGroups

public String[] getCacheGroups()

isFetchingDataRows

public boolean isFetchingDataRows()

prefetch

public SelectById<T> prefetch(String path,
                     int semantics)

Resets internal prefetches to the new value, which is a single prefetch with specified semantics.

Returns:

this object

prefetch

public SelectById<T> prefetch(PrefetchTreeNode prefetch)

Resets internal prefetches to the new value.

Returns:

this object

addPrefetch

public SelectById<T> addPrefetch(PrefetchTreeNode prefetch)

Merges prefetch into the query prefetch tree.

Returns:

this object

addPrefetch

public SelectById<T> addPrefetch(String path,
                        int semantics)

Merges a prefetch path with specified semantics into the query prefetch tree.

Returns:

this object

getPrefetches

public PrefetchTreeNode getPrefetches()

createReplacementQuery

protected Query createReplacementQuery(EntityResolver resolver)

Description copied from class: IndirectQuery

Creates a substitute query. An implementor is free to provide an arbitrary replacement query.

Specified by:

createReplacementQuery in class IndirectQuery

resolveId

protected Map<String,?> resolveId(ObjEntity entity)

resolveEntity

protected ObjEntity resolveEntity(EntityResolver resolver)