Package org.apache.cayenne.query

## Class SelectQuery<T>

- java.lang.Object
- - org.apache.cayenne.query.CacheableQuery
  - - org.apache.cayenne.query.AbstractQuery
    - - org.apache.cayenne.query.SelectQuery<T>

- All Implemented Interfaces:
    `Serializable`, `ParameterizedQuery`, `Query`, `Select<T>`
  Direct Known Subclasses:
    `PrefetchSelectQuery`

      public class SelectQuery<T>
      extends AbstractQuery
      implements ParameterizedQuery, Select<T>

  A query that selects persistent objects of a certain type or "raw data" (aka DataRows). Supports expression qualifier, multiple orderings and a number of other parameters that serve as runtime hints to Cayenne on how to optimize the fetch and result processing.
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected boolean` | `canReturnScalarValue` | Flag that indicates whether this query can return single value or it should always return some complex data (Object[] for now)
    `protected Collection<Property<?>>` | `columns` |
    `protected boolean` | `distinct` |
    `static boolean` | `DISTINCT_DEFAULT` |
    `static String` | `DISTINCT_PROPERTY` |
    `protected Expression` | `havingQualifier` |
    `protected List<Ordering>` | `orderings` |
    `protected Expression` | `qualifier` |

    - ### Fields inherited from class org.apache.cayenne.query.AbstractQuery

      `root`

    - ### Fields inherited from class org.apache.cayenne.query.CacheableQuery

      `logger`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `SelectQuery()` | Creates an empty SelectQuery.
    `SelectQuery​(Class<T> rootClass)` | Creates a SelectQuery that selects all objects of a given persistent class.
    `SelectQuery​(Class<T> rootClass, Expression qualifier)` | Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
    `SelectQuery​(Class<T> rootClass, Expression qualifier, List<? extends Ordering> orderings)` | Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
    `SelectQuery​(String objEntityName)` | Creates SelectQuery with `objEntityName` parameter.
    `SelectQuery​(String objEntityName, Expression qualifier)` | Creates SelectQuery with `objEntityName` and `qualifier` parameters.
    `SelectQuery​(String objEntityName, Expression qualifier, List<? extends Ordering> orderings)` | Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
    `SelectQuery​(DbEntity root)` | Creates a SelectQuery for the specified DbEntity.
    `SelectQuery​(DbEntity root, Expression qualifier)` | Creates a SelectQuery for the specified DbEntity with the given qualifier.
    `SelectQuery​(DbEntity root, Expression qualifier, List<? extends Ordering> orderings)` | Creates a SelectQuery for the specified DbEntity with the given qualifier and orderings.
    `SelectQuery​(ObjEntity root)` | Creates a SelectQuery with null qualifier, for the specifed ObjEntity
    `SelectQuery​(ObjEntity root, Expression qualifier)` | Creates a SelectQuery for the specified ObjEntity with the given qualifier.
    `SelectQuery​(ObjEntity root, Expression qualifier, List<? extends Ordering> orderings)` | Creates a SelectQuery for the specified ObjEntity with the given qualifier and orderings.

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `addOrdering​(String sortPathSpec, SortOrder order)` | Adds ordering specification to this query orderings.
    `void` | `addOrdering​(Ordering ordering)` | Adds ordering specification to this query orderings.
    `void` | `addOrderings​(Collection<? extends Ordering> orderings)` | Adds a list of orderings.
    `PrefetchTreeNode` | `addPrefetch​(String prefetchPath)` | Adds a prefetch with specified relationship path to the query.
    `void` | `addPrefetch​(PrefetchTreeNode prefetchElement)` | Adds a prefetch with specified relationship path to the query.
    `void` | `aliasPathSplits​(String path, String... aliases)` | Adds one or more aliases for the qualifier expression path.
    `void` | `andHavingQualifier​(Expression e)` | Adds specified HAVING qualifier to the existing HAVING qualifier joining it using "AND".
    `void` | `andQualifier​(Expression e)` | Adds specified qualifier to the existing qualifier joining it using "AND".
    `ResultBatchIterator<T>` | `batchIterator​(ObjectContext context, int size)` | Creates a ResultBatchIterator based on the provided context and batch size.
    `boolean` | `canReturnScalarValue()` |
    `void` | `clearOrderings()` | Clears all configured orderings.
    `void` | `clearPrefetches()` | Clears all stored prefetch paths.
    `SelectQuery<T>` | `createQuery​(Map<String,​?> parameters)` | Creates and returns a new SelectQuery built using this query as a prototype and substituting qualifier parameters with the values from the map.
    `SQLAction` | `createSQLAction​(SQLActionVisitor visitor)` | Calls "makeSelect" on the visitor.
    `static SelectQuery<DataRow>` | `dataRowQuery​(Class<?> rootClass)` |
    `static SelectQuery<DataRow>` | `dataRowQuery​(Class<?> rootClass, Expression qualifier)` | Creates a SelectQuery that selects DataRows that correspond to a given persistent class that match supplied qualifier.
    `static SelectQuery<DataRow>` | `dataRowQuery​(Class<?> rootClass, Expression qualifier, List<Ordering> orderings)` |
    `protected org.apache.cayenne.query.BaseQueryMetadata` | `getBaseMetaData()` |
    `Collection<Property<?>>` | `getColumns()` |
    `int` | `getFetchLimit()` | Returns the fetchLimit.
    `int` | `getFetchOffset()` | Returns the fetchOffset.
    `Expression` | `getHavingQualifier()` | Returns query HAVING qualifier.
    `QueryMetadata` | `getMetaData​(EntityResolver resolver)` | Returns default select parameters.
    `List<Ordering>` | `getOrderings()` | Returns a list of orderings used by this query.
    `int` | `getPageSize()` | Returns `pageSize` property.
    `PrefetchTreeNode` | `getPrefetchTree()` |
    `Expression` | `getQualifier()` | Returns query qualifier.
    `int` | `getStatementFetchSize()` |
    `void` | `initWithProperties​(Map<String,​?> properties)` | Initializes query parameters using a set of properties.
    `boolean` | `isDistinct()` | Returns true if this query returns distinct rows.
    `boolean` | `isFetchingDataRows()` | Returns `true` if this query should produce a list of data rows as opposed to DataObjects, `false` for DataObjects.
    `void` | `iterate​(ObjectContext context, ResultIteratorCallback<T> callback)` | Creates a ResultIterator based on the provided context and passes it to a callback for processing.
    `ResultIterator<T>` | `iterator​(ObjectContext context)` | Creates a ResultIterator based on the provided context.
    `void` | `orHavingQualifier​(Expression e)` | Adds specified HAVING qualifier to the existing HAVING qualifier joining it using "OR".
    `void` | `orQualifier​(Expression e)` | Adds specified qualifier to the existing qualifier joining it using "OR".
    `static <T> SelectQuery<T>` | `query​(Class<T> rootClass)` | Creates a SelectQuery that selects objects of a given persistent class.
    `static <T> SelectQuery<T>` | `query​(Class<T> rootClass, Expression qualifier)` | Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
    `static <T> SelectQuery<T>` | `query​(Class<T> rootClass, Expression qualifier, List<? extends Ordering> orderings)` | Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
    `SelectQuery<T>` | `queryWithParameters​(Map<String,​?> parameters)` | A shortcut for `queryWithParameters(Map, boolean)`that prunes parts of qualifier that have no parameter value set.
    `SelectQuery<T>` | `queryWithParameters​(Map<String,​?> parameters, boolean pruneMissing)` | Returns a query built using this query as a prototype, using a set of parameters to build the qualifier.
    `void` | `removeOrdering​(Ordering ordering)` | Removes ordering.
    `void` | `removePrefetch​(String prefetchPath)` | Removes prefetch.
    `void` | `route​(QueryRouter router, EntityResolver resolver, Query substitutedQuery)` | Routes itself and if there are any prefetches configured, creates prefetch queries and routes them as well.
    `List<T>` | `select​(ObjectContext context)` | Selects objects using provided context.
    `T` | `selectFirst​(ObjectContext context)` | Selects a single object using provided context.
    `T` | `selectOne​(ObjectContext context)` | Selects a single object using provided context.
    `void` | `setCanReturnScalarValue​(boolean canReturnScalarValue)` | Flag that indicates whether this query can return single value or it should always return some complex data (Object[] for now)
    `void` | `setColumns​(Collection<Property<?>> columns)` |
    `void` | `setColumns​(Property<?>... columns)` |
    `void` | `setDistinct​(boolean distinct)` | Sets `distinct` property that determines whether this query returns distinct row.
    `void` | `setFetchingDataRows​(boolean flag)` | Deprecated. since 4.0, use `dataRowQuery(Class, Expression)` to create DataRow query instead.
    `void` | `setFetchLimit​(int fetchLimit)` | Sets the fetchLimit.
    `void` | `setFetchOffset​(int fetchOffset)` |
    `void` | `setHavingQualifier​(Expression qualifier)` | Sets new query HAVING qualifier.
    `void` | `setPageSize​(int pageSize)` | Sets `pageSize` property.
    `void` | `setPrefetchTree​(PrefetchTreeNode prefetchTree)` |
    `void` | `setQualifier​(Expression qualifier)` | Sets new query qualifier.
    `void` | `setStatementFetchSize​(int size)` | Sets statement's fetch size (0 for default size)
    `void` | `setSuppressDistinct​(boolean suppressDistinct)` | Sets `distinct` property that determines whether this query returns distinct row.

    - ### Methods inherited from class org.apache.cayenne.query.AbstractQuery

      `getRoot, setRoot, toString`

    - ### Methods inherited from class org.apache.cayenne.query.CacheableQuery

      `getCacheGroup, getCacheStrategy, setCacheGroup, setCacheStrategy, useLocalCache, useLocalCache, useSharedCache, useSharedCache`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### DISTINCT_PROPERTY

          public static final String DISTINCT_PROPERTY

      See Also:
        Constant Field Values

    - #### DISTINCT_DEFAULT

          public static final boolean DISTINCT_DEFAULT

      See Also:
        Constant Field Values

    - #### qualifier

          protected Expression qualifier

    - #### orderings

          protected List<Ordering> orderings

    - #### distinct

          protected boolean distinct

    - #### columns

          protected Collection<Property<?>> columns

      Since:
        4.0

    - #### havingQualifier

          protected Expression havingQualifier

      Since:
        4.0

    - #### canReturnScalarValue

          protected boolean canReturnScalarValue

      Flag that indicates whether this query can return single value or it should always return some complex data (Object[] for now)

      Default value is true

      Since:
        4.0

  - ### Constructor Detail

    - #### SelectQuery

          public SelectQuery()

      Creates an empty SelectQuery.

    - #### SelectQuery

          public SelectQuery​(ObjEntity root)

      Creates a SelectQuery with null qualifier, for the specifed ObjEntity
      Parameters:
        `root` - the ObjEntity this SelectQuery is for.

    - #### SelectQuery

          public SelectQuery​(ObjEntity root,
                             Expression qualifier)

      Creates a SelectQuery for the specified ObjEntity with the given qualifier.
      Parameters:
        `root` - the ObjEntity this SelectQuery is for.
        `qualifier` - an Expression indicating which objects should be fetched

    - #### SelectQuery

          public SelectQuery​(ObjEntity root,
                             Expression qualifier,
                             List<? extends Ordering> orderings)

      Creates a SelectQuery for the specified ObjEntity with the given qualifier and orderings.
      Parameters:
        `root` - the ObjEntity this SelectQuery is for.
        `qualifier` - an Expression indicating which objects should be fetched.
        `orderings` - defines how to order the results, may be null.
      Since:
        3.1

    - #### SelectQuery

          public SelectQuery​(Class<T> rootClass)

      Creates a SelectQuery that selects all objects of a given persistent class.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.

    - #### SelectQuery

          public SelectQuery​(Class<T> rootClass,
                             Expression qualifier)

      Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.
        `qualifier` - an Expression indicating which objects should be fetched.

    - #### SelectQuery

          public SelectQuery​(Class<T> rootClass,
                             Expression qualifier,
                             List<? extends Ordering> orderings)

      Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.
        `qualifier` - an Expression indicating which objects should be fetched.
        `orderings` - defines how to order the results, may be null.
      Since:
        3.1

    - #### SelectQuery

          public SelectQuery​(DbEntity root)

      Creates a SelectQuery for the specified DbEntity.
      Parameters:
        `root` - the DbEntity this SelectQuery is for.
      Since:
        1.1

    - #### SelectQuery

          public SelectQuery​(DbEntity root,
                             Expression qualifier)

      Creates a SelectQuery for the specified DbEntity with the given qualifier.
      Parameters:
        `root` - the DbEntity this SelectQuery is for.
        `qualifier` - an Expression indicating which objects should be fetched.
      Since:
        1.1

    - #### SelectQuery

          public SelectQuery​(DbEntity root,
                             Expression qualifier,
                             List<? extends Ordering> orderings)

      Creates a SelectQuery for the specified DbEntity with the given qualifier and orderings.
      Parameters:
        `root` - the DbEntity this SelectQuery is for.
        `qualifier` - an Expression indicating which objects should be fetched.
        `orderings` - defines how to order the results, may be null.
      Since:
        3.1

    - #### SelectQuery

          public SelectQuery​(String objEntityName)

      Creates SelectQuery with `objEntityName` parameter.

    - #### SelectQuery

          public SelectQuery​(String objEntityName,
                             Expression qualifier)

      Creates SelectQuery with `objEntityName` and `qualifier` parameters.

    - #### SelectQuery

          public SelectQuery​(String objEntityName,
                             Expression qualifier,
                             List<? extends Ordering> orderings)

      Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
      Parameters:
        `objEntityName` - the name of the ObjEntity to fetch from.
        `qualifier` - an Expression indicating which objects should be fetched.
        `orderings` - defines how to order the results, may be null.
      Since:
        3.1

  - ### Method Detail

    - #### query

          public static <T> SelectQuery<T> query​(Class<T> rootClass)

      Creates a SelectQuery that selects objects of a given persistent class.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.
      Since:
        4.0

    - #### query

          public static <T> SelectQuery<T> query​(Class<T> rootClass,
                                                 Expression qualifier)

      Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.
        `qualifier` - an Expression indicating which objects should be fetched.
      Since:
        4.0

    - #### query

          public static <T> SelectQuery<T> query​(Class<T> rootClass,
                                                 Expression qualifier,
                                                 List<? extends Ordering> orderings)

      Creates a SelectQuery that selects objects of a given persistent class that match supplied qualifier.
      Parameters:
        `rootClass` - the Class of objects fetched by this query.
        `qualifier` - an Expression indicating which objects should be fetched.
        `orderings` - defines how to order the results, may be null.
      Since:
        4.0

    - #### dataRowQuery

          public static SelectQuery<DataRow> dataRowQuery​(Class<?> rootClass)

      Since:
        4.0

    - #### dataRowQuery

          public static SelectQuery<DataRow> dataRowQuery​(Class<?> rootClass,
                                                          Expression qualifier)

      Creates a SelectQuery that selects DataRows that correspond to a given persistent class that match supplied qualifier.
      Parameters:
        `rootClass` - the Class of objects that correspond to DataRows entity.
        `qualifier` - an Expression indicating which objects should be fetched.
      Since:
        4.0

    - #### dataRowQuery

          public static SelectQuery<DataRow> dataRowQuery​(Class<?> rootClass,
                                                          Expression qualifier,
                                                          List<Ordering> orderings)

      Since:
        4.0

    - #### 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>`

    - #### getMetaData

          public QueryMetadata getMetaData​(EntityResolver resolver)

      Description copied from class: `AbstractQuery`
      Returns default select parameters.
      Specified by:
        `getMetaData` in interface `Query`
      Overrides:
        `getMetaData` in class `AbstractQuery`
      Since:
        1.2

    - #### route

          public void route​(QueryRouter router,
                            EntityResolver resolver,
                            Query substitutedQuery)

      Routes itself and if there are any prefetches configured, creates prefetch queries and routes them as well.
      Specified by:
        `route` in interface `Query`
      Overrides:
        `route` in class `AbstractQuery`
      Since:
        1.2

    - #### createSQLAction

          public SQLAction createSQLAction​(SQLActionVisitor visitor)

      Calls "makeSelect" on the visitor.
      Specified by:
        `createSQLAction` in interface `Query`
      Specified by:
        `createSQLAction` in class `AbstractQuery`
      Since:
        1.2

    - #### initWithProperties

          public void initWithProperties​(Map<String,​?> properties)

      Initializes query parameters using a set of properties.
      Since:
        1.1

    - #### queryWithParameters

          public SelectQuery<T> queryWithParameters​(Map<String,​?> parameters)

      A shortcut for `queryWithParameters(Map, boolean)`that prunes parts of qualifier that have no parameter value set.

    - #### queryWithParameters

          public SelectQuery<T> queryWithParameters​(Map<String,​?> parameters,
                                                    boolean pruneMissing)

      Returns a query built using this query as a prototype, using a set of parameters to build the qualifier.
      See Also:
        `parameter substitution.`

    - #### createQuery

          public SelectQuery<T> createQuery​(Map<String,​?> parameters)

      Creates and returns a new SelectQuery built using this query as a prototype and substituting qualifier parameters with the values from the map.
      Specified by:
        `createQuery` in interface `ParameterizedQuery`
      Since:
        1.1

    - #### addOrdering

          public void addOrdering​(Ordering ordering)

      Adds ordering specification to this query orderings.

    - #### addOrderings

          public void addOrderings​(Collection<? extends Ordering> orderings)

      Adds a list of orderings.

    - #### addOrdering

          public void addOrdering​(String sortPathSpec,
                                  SortOrder order)

      Adds ordering specification to this query orderings.
      Since:
        3.0

    - #### removeOrdering

          public void removeOrdering​(Ordering ordering)

      Removes ordering.
      Since:
        1.1

    - #### getOrderings

          public List<Ordering> getOrderings()

      Returns a list of orderings used by this query.

    - #### clearOrderings

          public void clearOrderings()

      Clears all configured orderings.

    - #### isDistinct

          public boolean isDistinct()

      Returns true if this query returns distinct rows.

    - #### setDistinct

          public void setDistinct​(boolean distinct)

      Sets `distinct` property that determines whether this query returns distinct row.

    - #### setSuppressDistinct

          public void setSuppressDistinct​(boolean suppressDistinct)

      Sets `distinct` property that determines whether this query returns distinct row.

    - #### aliasPathSplits

          public void aliasPathSplits​(String path,
                                      String... aliases)

      Adds one or more aliases for the qualifier expression path. Aliases serve to instruct Cayenne to generate separate sets of joins for overlapping paths, that maybe needed for complex conditions. An example of an implicit splits is this method: `ExpressionFactory.matchAllExp(String, Object...)`.
      Since:
        3.0

    - #### getPrefetchTree

          public PrefetchTreeNode getPrefetchTree()

      Since:
        1.2

    - #### setPrefetchTree

          public void setPrefetchTree​(PrefetchTreeNode prefetchTree)

      Since:
        1.2

    - #### addPrefetch

          public void addPrefetch​(PrefetchTreeNode prefetchElement)

      Adds a prefetch with specified relationship path to the query.
      Since:
        4.0

    - #### addPrefetch

          public PrefetchTreeNode addPrefetch​(String prefetchPath)

      Adds a prefetch with specified relationship path to the query.
      Since:
        1.2 signature changed to return created PrefetchTreeNode.

    - #### clearPrefetches

          public void clearPrefetches()

      Clears all stored prefetch paths.

    - #### removePrefetch

          public void removePrefetch​(String prefetchPath)

      Removes prefetch.
      Since:
        1.1

    - #### isFetchingDataRows

          public 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.

    - #### setFetchingDataRows

          public void setFetchingDataRows​(boolean flag)

      Deprecated.
      since 4.0, use `dataRowQuery(Class, Expression)` to create DataRow query instead.
      Sets query result type. If `flag` parameter is `true`, then results will be in the form of data rows.

      Note that if the root of this query is a `DbEntity`, this setting has no effect, and data rows are always fetched.

    - #### getFetchOffset

          public int getFetchOffset()

      Returns the fetchOffset.
      Since:
        3.0

    - #### getFetchLimit

          public int getFetchLimit()

      Returns the fetchLimit.

    - #### setFetchLimit

          public void setFetchLimit​(int fetchLimit)

      Sets the fetchLimit.

    - #### setFetchOffset

          public void setFetchOffset​(int fetchOffset)

      Since:
        3.0

    - #### getPageSize

          public int getPageSize()

      Returns `pageSize` property. See setPageSize for more details.

    - #### setPageSize

          public void setPageSize​(int pageSize)

      Sets `pageSize` property. By setting a page size, the Collection returned by performing a query will return hollow DataObjects. This is considerably faster and uses a tiny fraction of the memory compared to a non-paged query when large numbers of objects are returned in the result. When a hollow DataObject is accessed all DataObjects on the same page will be faulted into memory. There will be a small delay when faulting objects while the data is fetched from the data source, but otherwise you do not need to do anything special to access data in hollow objects. The first page is always faulted into memory immediately.
      Parameters:
        `pageSize` - The pageSize to set

    - #### setStatementFetchSize

          public void setStatementFetchSize​(int size)

      Sets statement's fetch size (0 for default size)
      Since:
        3.0

    - #### getStatementFetchSize

          public int getStatementFetchSize()

      Returns:
        statement's fetch size
      Since:
        3.0

    - #### setQualifier

          public void setQualifier​(Expression qualifier)

      Sets new query qualifier.

    - #### getQualifier

          public Expression getQualifier()

      Returns query qualifier.

    - #### andQualifier

          public void andQualifier​(Expression e)

      Adds specified qualifier to the existing qualifier joining it using "AND".

    - #### orQualifier

          public void orQualifier​(Expression e)

      Adds specified qualifier to the existing qualifier joining it using "OR".

    - #### setColumns

          public void setColumns​(Collection<Property<?>> columns)

      Since:
        4.0
      See Also:
        `setCanReturnScalarValue(boolean)`

    - #### setColumns

          public void setColumns​(Property<?>... columns)

      Since:
        4.0

    - #### setCanReturnScalarValue

          public void setCanReturnScalarValue​(boolean canReturnScalarValue)

      Flag that indicates whether this query can return single value or it should always return some complex data (Object[] for now)

      Default value is true

      Parameters:
        `canReturnScalarValue` - can this query return single value
      Since:
        4.0
      See Also:
        `setColumns(java.util.Collection<org.apache.cayenne.exp.Property<?>>)`

    - #### canReturnScalarValue

          public boolean canReturnScalarValue()

      Returns:
        can this query return single value
      Since:
        4.0

    - #### getColumns

          public Collection<Property<?>> getColumns()

      Since:
        4.0

    - #### setHavingQualifier

          public void setHavingQualifier​(Expression qualifier)

      Sets new query HAVING qualifier.
      Since:
        4.0

    - #### getHavingQualifier

          public Expression getHavingQualifier()

      Returns query HAVING qualifier.
      Since:
        4.0

    - #### andHavingQualifier

          public void andHavingQualifier​(Expression e)

      Adds specified HAVING qualifier to the existing HAVING qualifier joining it using "AND".
      Since:
        4.0

    - #### orHavingQualifier

          public void orHavingQualifier​(Expression e)

      Adds specified HAVING qualifier to the existing HAVING qualifier joining it using "OR".
      Since:
        4.0

    - #### getBaseMetaData

          protected org.apache.cayenne.query.BaseQueryMetadata getBaseMetaData()

      Specified by:
        `getBaseMetaData` in class `CacheableQuery`