org.apache.cayenne.query
Interface Query

All Superinterfaces:
Serializable
All Known Subinterfaces:
ParameterizedQuery
All Known Implementing Classes:
AbstractQuery, BatchQuery, DeleteBatchQuery, DeleteQuery, EJBQLQuery, EOQuery, EOSQLQuery, IndirectQuery, InsertBatchQuery, NamedQuery, ObjectIdQuery, PrefetchSelectQuery, ProcedureQuery, QualifiedQuery, QueryChain, RefreshQuery, RelationshipQuery, SelectQuery, SQLTemplate, UpdateBatchQuery, UpdateQuery

public interface Query
extends Serializable

Defines minimal API of a query descriptor that is executable via Cayenne.


Method Summary
 SQLAction createSQLAction(SQLActionVisitor visitor)
          A callback method invoked by Cayenne during the final execution phase of the query run.
 QueryMetadata getMetaData(EntityResolver resolver)
          Returns query runtime parameters.
 String getName()
          Returns a symbolic name of the query.
 void route(QueryRouter router, EntityResolver resolver, Query substitutedQuery)
          A callback method invoked by Cayenne during the routing phase of the query execution.
 

Method Detail

getMetaData

QueryMetadata getMetaData(EntityResolver resolver)
Returns query runtime parameters. The method is called at various stages of the execution by Cayenne access stack to retrieve query parameters. EntityResolver instance is passed to this method, meaning that the query doesn't need to store direct references to Cayenne mapping objects and can resolve them at runtime.

Since:
1.2

route

void route(QueryRouter router,
           EntityResolver resolver,
           Query substitutedQuery)
A callback method invoked by Cayenne during the routing phase of the query execution. Mapping of DataNodes is provided by QueryRouter. Query should use a QueryRouter.route(QueryEngine, Query, Query) callback method to route itself. Query can create one or more substitute queries or even provide its own QueryEngine to execute itself.

Since:
1.2

createSQLAction

SQLAction createSQLAction(SQLActionVisitor visitor)
A callback method invoked by Cayenne during the final execution phase of the query run. A concrete query implementation is given a chance to decide how it should be handled. Implementors can pick an appropriate method of the SQLActionVisitor to handle itself, create a custom SQLAction of its own, or substitute itself with another query that should be used for SQLAction construction.

Since:
1.2

getName

String getName()
Returns a symbolic name of the query. The name may be used as a key to find queries stored in the DataMap. Some query implementors reuse the name as a QueryMetadata cache key. Generally the name can be null.

Since:
1.1


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