org.apache.openjpa.kernel
Interface StoreQuery.Executor

All Known Implementing Classes:

AbstractStoreQuery.AbstractExecutor

Enclosing interface:

StoreQuery

public static interface StoreQuery.Executor

An executor provides a uniform interface to the mechanism for executing either an in-memory or datastore query. In the common case, the executeQuery(org.apache.openjpa.kernel.StoreQuery, java.lang.Object[], org.apache.openjpa.kernel.StoreQuery.Range) method will be called before other methods, though this is not guaranteed.

Author:

Marc Prud'hommeaux

Method Summary

Number	executeDelete(StoreQuery q, Object[] params) Deleted the objects that result from the execution of the query, retuning the number of objects that were deleted.
ResultObjectProvider	executeQuery(StoreQuery q, Object[] params, StoreQuery.Range range) Return the result of executing this query with the given parameter values.
Number	executeUpdate(StoreQuery q, Object[] params) Updates the objects that result from the execution of the query, retuning the number of objects that were updated.
ClassMetaData[]	getAccessPathMetaDatas(StoreQuery q) Return an array of all persistent classes used in this query, or empty array if unknown.
String	getAlias(StoreQuery q) If this is not a projection but the candidate results are placed into a result class with an alias, return that alias.
boolean[]	getAscending(StoreQuery q) Return the ordering direction for all ordering clauses, or empty array if none.
String[]	getDataStoreActions(StoreQuery q, Object[] params, StoreQuery.Range range) Return a description of the commands that will be sent to the datastore in order to execute the query.
int	getOperation(StoreQuery q) Returns the operation this executor is meant to execute.
Object	getOrderingValue(StoreQuery q, Object[] params, Object resultObject, int orderIndex) Extract the value of the orderIndexth ordering expression in Query#getOrderingClauses from the given result object.
LinkedMap	getParameterTypes(StoreQuery q) Return a map of parameter names to types.
String[]	getProjectionAliases(StoreQuery q) Return the alias for each projection element, or empty array if not a projection.
Class[]	getProjectionTypes(StoreQuery q) Return the expected types of the projections used by this query, or an empty array if not a projection.
void	getRange(StoreQuery q, Object[] params, StoreQuery.Range range) Mutate the given range to set any range information stored in the query string and/or parameters.
Class	getResultClass(StoreQuery q) Returns the result class, if any.
Map	getUpdates(StoreQuery q) Return a map of FieldMetaData to update Constants, in cases where this query is for a bulk update.
boolean	hasGrouping(StoreQuery q) Whether the compiled query has grouping.
boolean	isAggregate(StoreQuery q) Return true if the compiled query is an aggregate.
boolean	isPacking(StoreQuery q) Return true if this executor packs projections into the result class itself.
void	validate(StoreQuery q) Validate components of query.

Method Detail

executeQuery

ResultObjectProvider executeQuery(StoreQuery q,
                                  Object[] params,
                                  StoreQuery.Range range)

Return the result of executing this query with the given parameter values. If this query is a projection and this executor does not pack results itself, each element of the returned result object provider should be an object array containing the projection values.

Parameters:

lrs - true if the query result should be treated as a large result set, assuming the query is not an aggregate and does not have grouping

See Also:

isPacking(org.apache.openjpa.kernel.StoreQuery)

executeDelete

Number executeDelete(StoreQuery q,
                     Object[] params)

Deleted the objects that result from the execution of the query, retuning the number of objects that were deleted.

executeUpdate

Number executeUpdate(StoreQuery q,
                     Object[] params)

Updates the objects that result from the execution of the query, retuning the number of objects that were updated.

getDataStoreActions

String[] getDataStoreActions(StoreQuery q,
                             Object[] params,
                             StoreQuery.Range range)

Return a description of the commands that will be sent to the datastore in order to execute the query.

validate

void validate(StoreQuery q)

Validate components of query.

getRange

void getRange(StoreQuery q,
              Object[] params,
              StoreQuery.Range range)

Mutate the given range to set any range information stored in the query string and/or parameters.

getOrderingValue

Object getOrderingValue(StoreQuery q,
                        Object[] params,
                        Object resultObject,
                        int orderIndex)

Extract the value of the orderIndexth ordering expression in Query#getOrderingClauses from the given result object. The result object will be an object from the result object provider returned from executeQuery(org.apache.openjpa.kernel.StoreQuery, java.lang.Object[], org.apache.openjpa.kernel.StoreQuery.Range). This method is used when several result lists have to be merged in memory. If this exeuctor's parent query supports executors on abstract or interface classes, this method will not be used.

See Also:

StoreQuery.supportsAbstractExecutors()

getAscending

boolean[] getAscending(StoreQuery q)

Return the ordering direction for all ordering clauses, or empty array if none.

isPacking

boolean isPacking(StoreQuery q)

Return true if this executor packs projections into the result class itself. Executors for query languages that allow projections without result clauses must return true and perform the result packing themselves.

getAlias

String getAlias(StoreQuery q)

If this is not a projection but the candidate results are placed into a result class with an alias, return that alias.

getProjectionAliases

String[] getProjectionAliases(StoreQuery q)

Return the alias for each projection element, or empty array if not a projection.

getProjectionTypes

Class[] getProjectionTypes(StoreQuery q)

Return the expected types of the projections used by this query, or an empty array if not a projection.

getAccessPathMetaDatas

ClassMetaData[] getAccessPathMetaDatas(StoreQuery q)

Return an array of all persistent classes used in this query, or empty array if unknown.

getOperation

int getOperation(StoreQuery q)

Returns the operation this executor is meant to execute.

See Also:

QueryOperations

isAggregate

boolean isAggregate(StoreQuery q)

Return true if the compiled query is an aggregate.

hasGrouping

boolean hasGrouping(StoreQuery q)

Whether the compiled query has grouping.

getParameterTypes

LinkedMap getParameterTypes(StoreQuery q)

Return a map of parameter names to types. The returned Map.entrySet()'s Iterator must return values in the order in which they were declared or used.

getResultClass

Class getResultClass(StoreQuery q)

Returns the result class, if any.

getUpdates

Map getUpdates(StoreQuery q)

Return a map of FieldMetaData to update Constants, in cases where this query is for a bulk update.