Package org.apache.cayenne.query

Class SQLSelect<T>

    • Field Detail

      • persistentType

        protected Class<T> persistentType

      • dataMapName

        protected String dataMapName

      • cacheGroup

        protected String cacheGroup

      • positionalParams

        protected List<Object> positionalParams

      • limit

        protected int limit

      • offset

        protected int offset

      • pageSize

        protected int pageSize

      • statementFetchSize

        protected int statementFetchSize

      • queryTimeout

        protected int queryTimeout

    • Constructor Detail

      • SQLSelect

        public SQLSelect​(String sql)

      • SQLSelect

        public SQLSelect​(Class<T> persistentType,
                 String sql)

    • Method Detail

      • dataRowQuery

        public static SQLSelect<DataRow> dataRowQuery​(String sql)
        Creates a query that selects DataRows and uses default routing.

      • dataRowQuery

        public static SQLSelect<DataRow> dataRowQuery​(String sql,
                                              Class<?>... types)
        Creates a query that selects DataRows and uses default routing.
        Since:
        4.1

      • dataRowQuery

        public static SQLSelect<DataRow> dataRowQuery​(String dataMapName,
                                              String sql,
                                              Class<?>... types)
        Creates a query that selects DataRows and uses routing based on the provided DataMap name.
        Since:
        4.1

      • dataRowQuery

        public static SQLSelect<DataRow> dataRowQuery​(String dataMapName,
                                              String sql)
        Creates a query that selects DataRows and uses routing based on the provided DataMap name.

      • query

        public static <T> SQLSelect<T> query​(Class<T> type,
                                     String sql)
        Creates a query that selects DataObjects.

      • scalarQuery

        public static <T> SQLSelect<T> scalarQuery​(String sql,
                                           Class<T> type)
        Creates query that selects scalar value and uses default routing
        Since:
        4.1

      • scalarQuery

        public static <T> SQLSelect<T> scalarQuery​(String sql,
                                           String dataMapName,
                                           Class<T> type)
        Creates query that selects scalar value and uses default routing
        Since:
        4.1

      • columnQuery

        public static SQLSelect<Object[]> columnQuery​(String sql)
        Creates query that selects scalar values (as Object[]) and uses default routing
        Since:
        4.2

      • columnQuery

        public static SQLSelect<Object[]> columnQuery​(String sql,
                                              String dataMapName)
        Creates query that selects scalar values (as Object[]) and uses routing based on the provided DataMap name.
        Since:
        4.2

      • columnQuery

        public static SQLSelect<Object[]> columnQuery​(String sql,
                                              Class<?>... types)
        Creates query that selects scalar values (as Object[]) and uses default routing
        Since:
        4.2

      • columnQuery

        public static SQLSelect<Object[]> columnQuery​(String sql,
                                              String dataMapName,
                                              Class<?>... types)
        Creates query that selects scalar values (as Object[]) and uses routing based on the provided DataMap name.
        Since:
        4.2

      • select

        public List<T> select​(ObjectContext context)
        Description copied from interface: Select
        Selects objects using provided context.

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

        Specified by:
        select in interface Select<T>

      • selectOne

        public T selectOne​(ObjectContext context)
        Description copied from interface: Select
        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.

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

        Specified by:
        selectOne in interface Select<T>

      • selectFirst

        public T selectFirst​(ObjectContext context)
        Description copied from interface: Select
        Selects a single object using provided context. The query itself can match any number of objects, but will return only the first one. It returns null if no objects were matched.

        If it matched more than one object, the first object from the list is returned. This makes 'selectFirst' different from Select.selectOne(ObjectContext), which would throw in this situation. 'selectFirst' is useful e.g. when the query is ordered and we only want to see the first object (e.g. "most recent news article"), etc.

        Selecting the first object via "Select.selectFirst(ObjectContext)" is more comprehensible than selecting via "ObjectContext.selectFirst(Select)", because implementations of "Select" set fetch size limit to one.

        Specified by:
        selectFirst in interface Select<T>

      • iterate

        public void iterate​(ObjectContext context,
                    ResultIteratorCallback<T> callback)
        Description copied from interface: Select
        Creates a ResultIterator based on the provided context and passes it to a callback for processing. The caller does not need to worry about closing the iterator. This method takes care of it.

        Essentially the inversion of "ObjectContext.iterate(Select, ResultIteratorCallback)".

        Specified by:
        iterate in interface Select<T>

      • iterator

        public ResultIterator<T> iterator​(ObjectContext context)
        Description copied from interface: Select
        Creates a ResultIterator based on the provided context. It is usually backed by an open result set and is useful for processing of large data sets, preserving a constant memory footprint. The caller must wrap iteration in try/finally (or try-with-resources for Java 1.7 and higher) and close the ResultIterator explicitly. Or use Select.iterate(ObjectContext, ResultIteratorCallback) as an alternative.

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

        Specified by:
        iterator in interface Select<T>

      • batchIterator

        public ResultBatchIterator<T> batchIterator​(ObjectContext context,
                                            int size)
        Description copied from interface: Select
        Creates a ResultBatchIterator based on the provided context and batch size. It is usually backed by an open result set and is useful for processing of large data sets, preserving a constant memory footprint. The caller must wrap iteration in try/finally (or try-with-resources for Java 1.7 and higher) and close the ResultBatchIterator explicitly.
        Specified by:
        batchIterator in interface Select<T>

      • isFetchingDataRows

        public boolean isFetchingDataRows()

      • getSql

        public String getSql()

      • append

        public SQLSelect<T> append​(String sqlChunk)
        Appends a piece of SQL to the previously stored SQL template.

      • paramsArray

        public SQLSelect<T> paramsArray​(Object... params)
        Initializes positional parameters of the query. Parameters are bound in the order they are found in the SQL template. If a given parameter name is used more than once, only the first occurrence is treated as "position", subsequent occurrences are bound with the same value as the first one. If template parameters count is different from the array parameter count, an exception will be thrown.

        Note that calling this method will reset any previously set *named* parameters.

      • paramsList

        public SQLSelect<T> paramsList​(List<Object> params)
        Initializes positional parameters of the query. Parameters are bound in the order they are found in the SQL template. If a given parameter name is used more than once, only the first occurrence is treated as "position", subsequent occurrences are bound with the same value as the first one. If template parameters count is different from the list parameter count, an exception will be thrown.

        Note that calling this method will reset any previously set *named* parameters.

      • getParams

        public Map<String,​Object> getParams()
        Returns a potentially immmutable map of named parameters that will be bound to SQL.

      • getPositionalParams

        public List<Object> getPositionalParams()
        Returns a potentially immmutable list of positional parameters that will be bound to SQL.

      • localCache

        public SQLSelect<T> localCache()
        Instructs Cayenne to look for query results in the "local" cache when running the query. This is a short-hand notation for: 
         query.cacheStrategy(QueryCacheStrategy.LOCAL_CACHE);

      • localCache

        public SQLSelect<T> localCache​(String cacheGroup)
        Instructs Cayenne to look for query results in the "local" cache when running the query. This is a short-hand notation for: 
         query.cacheStrategy(QueryCacheStrategy.LOCAL_CACHE, cacheGroup);

      • sharedCache

        public SQLSelect<T> sharedCache()
        Instructs Cayenne to look for query results in the "shared" cache when running the query. This is a short-hand notation for: 
         query.cacheStrategy(QueryCacheStrategy.SHARED_CACHE);

      • sharedCache

        public SQLSelect<T> sharedCache​(String cacheGroup)
        Instructs Cayenne to look for query results in the "shared" cache when running the query. This is a short-hand notation for: 
         query.cacheStrategy(QueryCacheStrategy.SHARED_CACHE, cacheGroup);

      • getCacheGroup

        public String getCacheGroup()

      • getColumnNameCaps

        public CapsStrategy getColumnNameCaps()
        Returns a column name capitalization policy applied to selecting queries. This is used to simplify mapping of the queries like "SELECT * FROM ...", ensuring that a chosen Cayenne column mapping strategy (e.g. all column names in uppercase) is portable across database engines that can have varying default capitalization. Default (null) value indicates that column names provided in result set are used unchanged.

      • columnNameCaps

        public SQLSelect<T> columnNameCaps​(CapsStrategy columnNameCaps)
        Sets a column name capitalization policy applied to selecting queries. This is used to simplify mapping of the queries like "SELECT * FROM ...", ensuring that a chosen Cayenne column mapping strategy (e.g. all column names in uppercase) is portable across database engines that can have varying default capitalization. Default (null) value indicates that column names provided in result set are used unchanged.

        Note that while a non-default setting is useful for queries that do not rely on a #result directive to describe columns, it works for all SQLTemplates the same way.

      • getLimit

        public int getLimit()

      • limit

        public SQLSelect<T> limit​(int fetchLimit)

      • getOffset

        public int getOffset()

      • offset

        public SQLSelect<T> offset​(int fetchOffset)

      • getPageSize

        public int getPageSize()

      • pageSize

        public SQLSelect<T> pageSize​(int pageSize)

      • statementFetchSize

        public SQLSelect<T> statementFetchSize​(int size)
        Sets JDBC statement's fetch size (0 for no default size)

      • queryTimeout

        public SQLSelect<T> queryTimeout​(int queryTimeout)
        Sets query timeout
        Since:
        4.2

      • getStatementFetchSize

        public int getStatementFetchSize()
        Returns:
        JBDC statement's fetch size

      • getQueryTimeout

        public int getQueryTimeout()

      • addPrefetch

        public SQLSelect<T> addPrefetch​(String path,
                                int semantics)
        Merges a prefetch path with specified semantics into the query prefetch tree.
        Parameters:
        path - Path expression
        semantics - Defines a strategy to prefetch relationships. See PrefetchTreeNode
        Returns:
        this object
        Since:
        4.1

      • addPrefetch

        public SQLSelect<T> addPrefetch​(PrefetchTreeNode node)
        Merges a prefetch into the query prefetch tree.
        Parameters:
        node - Prefetch which will added to query prefetch tree
        Returns:
        this object
        Since:
        4.1

      • map

        public <E> SQLSelect<E> map​(Function<T,​E> mapper)
        Map result of this query by processing with a given function.
        Could be used to map plain Object[] to some domain-specific object.
        Note: this method could be called multiple time, result will be mapped by all functions in the call order.
        Type Parameters:
        E - new result type
        Parameters:
        mapper - function that maps result to the required type.
        Returns:
        this query with changed result type
        Since:
        4.2
        See Also:
        ColumnSelect.map(Function)