Package org.apache.cayenne.query

Interface QueryMetadata

All Known Implementing Classes:
QueryMetadataProxy, SQLTemplateMetadata
public interface QueryMetadata
Provides a common interface for accessing query metadata.
Since:
1.2

  • Field Details

    • FETCH_LIMIT_PROPERTY

      static final String FETCH_LIMIT_PROPERTY
      Defines the name of the property for the query fetch limit .
      See Also:

    • FETCH_LIMIT_DEFAULT

      static final int FETCH_LIMIT_DEFAULT
      Defines default query fetch limit, which is zero, meaning that all matching rows should be fetched.
      See Also:

    • FETCH_OFFSET_PROPERTY

      static final String FETCH_OFFSET_PROPERTY
      Defines the name of the property for the query fetch offset.
      Since:
      3.0
      See Also:

    • FETCH_OFFSET_DEFAULT

      static final int FETCH_OFFSET_DEFAULT
      Defines default query fetch start index, which is 0, meaning that matching rows selected starting from the first.
      Since:
      3.0
      See Also:

    • QUERY_TIMEOUT_DEFAULT

      static final int QUERY_TIMEOUT_DEFAULT
      See Also:

    • PAGE_SIZE_PROPERTY

      static final String PAGE_SIZE_PROPERTY
      Defines the name of the property for the query page size.
      See Also:

    • PAGE_SIZE_DEFAULT

      static final int PAGE_SIZE_DEFAULT
      Defines default query page size, which is zero for no pagination.
      See Also:

    • FETCHING_DATA_ROWS_PROPERTY

      static final String FETCHING_DATA_ROWS_PROPERTY
      See Also:

    • FETCHING_DATA_ROWS_DEFAULT

      static final boolean FETCHING_DATA_ROWS_DEFAULT
      See Also:

    • CACHE_STRATEGY_PROPERTY

      static final String CACHE_STRATEGY_PROPERTY
      Since:
      3.0
      See Also:

    • CACHE_GROUPS_PROPERTY

      static final String CACHE_GROUPS_PROPERTY
      Since:
      3.0
      See Also:

    • STATEMENT_FETCH_SIZE_PROPERTY

      static final String STATEMENT_FETCH_SIZE_PROPERTY
      Defines the name of the property for the query fetch size.
      Since:
      3.0
      See Also:

    • STATEMENT_FETCH_SIZE_DEFAULT

      static final int STATEMENT_FETCH_SIZE_DEFAULT
      Defines default query fetch start index, which is 0, meaning that matching rows selected starting from the first.
      Since:
      3.0
      See Also:

  • Method Details

    • getClassDescriptor

      ClassDescriptor getClassDescriptor()
      Since:
      3.0

    • getObjEntity

      ObjEntity getObjEntity()
      Returns an ObjEntity associated with a query or null if no such entity exists.

    • getDbEntity

      DbEntity getDbEntity()
      Returns a DbEntity associated with a query or null if no such entity exists.

    • getProcedure

      Procedure getProcedure()
      Returns a Procedure associated with a query or null if no such procedure exists.

    • getDataMap

      DataMap getDataMap()
      Returns a DataMap associated with a query or null if no such DataMap exists.

    • getCacheStrategy

      QueryCacheStrategy getCacheStrategy()
      Returns a caching strategy for this query.
      Since:
      3.0

    • getCacheKey

      String getCacheKey()
      Returns a String that uniquely identifies this query for the purposes of result caching. If null is returned, no caching is performed.

    • getCacheGroup

      String getCacheGroup()
      Returns an optional cache "group". Cache groups allow to invalidate query caches in bulk on different events.
      Since:
      4.0

    • isFetchingDataRows

      boolean isFetchingDataRows()
      Returns true if this query should produce a list of data rows as opposed to DataObjects, false for DataObjects. This is a hint to QueryEngine executing this query.

    • isRefreshingObjects

      boolean isRefreshingObjects()
      Returns true if the query results should replace any currently cached values, returns false otherwise. If isFetchingDataRows() returns true, this setting is not applicable and has no effect.

    • getPageSize

      int getPageSize()
      Returns query page size. Page size is a hint to Cayenne that query should be performed page by page, instead of retrieving all results at once. If the value returned is less than or equal to zero, no paging should occur.

    • getFetchOffset

      int getFetchOffset()
      Specifies a start of a range when fetching a subset of records.
      Since:
      3.0

    • getFetchLimit

      int getFetchLimit()
      Returns the limit on the maximum number of records that can be returned by this query. If the actual number of rows in the result exceeds the fetch limit, they will be discarded. One possible use of fetch limit is using it as a safeguard against large result sets that may lead to the application running out of memory, etc. If a fetch limit is greater or equal to zero, all rows will be returned.
      Returns:
      the limit on the maximum number of records that can be returned by this query

    • getOriginatingQuery

      Query getOriginatingQuery()
      Returns a query that originated this query. Originating query is a query whose result is needed to obtain the result of the query owning this metadata. Most often than not the returned value is null. One example of non-null originating query is a query for a range of objects in a previously fetched paginated list. The query that fetched the original paginated list is an "originated" query. It may be used to restore a list that got lost due to a cache overflow, etc.
      Since:
      4.0

    • getPrefetchTree

      PrefetchTreeNode getPrefetchTree()
      Returns a root node of prefetch tree used by this query, or null of no prefetches are configured.

    • getPathSplitAliases

      Map<String,String> getPathSplitAliases()
      Returns a map of aliases vs. expression subpaths that is used to build split joins.
      Since:
      3.0

    • getResultSetMapping

      List<Object> getResultSetMapping()
      Returns an optional list of result set mapping hints. Elements in the list can be either EntityResultSegment or ScalarResultSegment. The returned list can be null.
      Since:
      3.0

    • setResultSetMapping

      default void setResultSetMapping(List<Object> resultSetMapping)
      Since:
      4.2

    • isSingleResultSetMapping

      boolean isSingleResultSetMapping()
      Returns:
      should the result be mapped to single object (scalar or entity)
      Since:
      4.0
      See Also:

    • getStatementFetchSize

      int getStatementFetchSize()
      Returns:
      statement's fetch size
      Since:
      3.0

    • getQueryTimeout

      int getQueryTimeout()
      Returns:
      query timeout
      Since:
      4.2

    • isSuppressingDistinct

      boolean isSuppressingDistinct()
      Since:
      4.0

    • getResultMapper

      default Function<?,?> getResultMapper()
      Since:
      4.2