Package org.eclipse.persistence.queries

Class ReadAllQuery

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    Direct Known Subclasses:
    ReportQuery
    public class ReadAllQuery
extends ObjectLevelReadQuery

    Purpose: Concrete class for all read queries involving a collection of objects.

    Responsibilities: Return a container of the objects generated by the query. Implements the inheritance feature when dealing with abstract descriptors

    See Also:
    Serialized Form
    Author:
    Yvon Lavoie
    Since:
    TOPLink/Java 1.0

    • Field Detail

      • containerPolicy

        protected org.eclipse.persistence.internal.queries.ContainerPolicy containerPolicy
        Used for collection and stream support.

      • startWithExpression

        protected Expression startWithExpression
        Used for Oracle HierarchicalQuery support

      • connectByExpression

        protected Expression connectByExpression

      • orderSiblingsByExpressions

        protected java.util.List<Expression> orderSiblingsByExpressions

    • Constructor Detail

      • ReadAllQuery

        public ReadAllQuery()
        PUBLIC: Return a new read all query. A reference class must be specified before execution. It is better to provide the class and expression builder on construction to ensure a single expression builder is used. If no selection criteria is specified this will read all objects of the class from the database.

      • ReadAllQuery

        public ReadAllQuery​(java.lang.Class classToRead)
        PUBLIC: Return a new read all query. It is better to provide the class and expression builder on construction to ensure a single expression builder is used. If no selection criteria is specified this will read all objects of the class from the database.

      • ReadAllQuery

        public ReadAllQuery​(java.lang.Class classToRead,
                    Expression selectionCriteria)
        PUBLIC: Return a new read all query for the class and the selection criteria.

      • ReadAllQuery

        public ReadAllQuery​(java.lang.Class classToRead,
                    ExpressionBuilder builder)
        PUBLIC: Return a new read all query for the class. The expression builder must be used for all associated expressions used with the query.

      • ReadAllQuery

        public ReadAllQuery​(java.lang.Class classToRead,
                    Call call)
        PUBLIC: Return a new read all query. The call represents a database interaction such as SQL, Stored Procedure.

      • ReadAllQuery

        public ReadAllQuery​(java.lang.Object exampleObject,
                    QueryByExamplePolicy policy)
        PUBLIC: Return a query by example query to find all objects matching the attributes of the example object.

      • ReadAllQuery

        public ReadAllQuery​(ExpressionBuilder builder)
        PUBLIC: The expression builder should be provide on creation to ensure only one is used.

      • ReadAllQuery

        public ReadAllQuery​(Call call)
        PUBLIC: Create a read all query with the database call.

    • Method Detail

      • addAscendingOrdering

        public void addAscendingOrdering​(java.lang.String queryKeyName)
        PUBLIC: Order the query results by the object's attribute or query key name.

      • cacheResult

        public void cacheResult​(java.lang.Object unwrappedOriginal)
        INTERNAL:

        This method is called by the object builder when building an original. It will cause the original to be cached in the query results if the query is set to do so.

        Specified by:
        cacheResult in class ReadQuery

      • checkEarlyReturnLocal

        protected java.lang.Object checkEarlyReturnLocal​(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                                 org.eclipse.persistence.internal.sessions.AbstractRecord translationRow)
        INTERNAL: The cache check is done before the prepare as a hit will not require the work to be done.
        Specified by:
        checkEarlyReturnLocal in class ObjectLevelReadQuery

      • checkCustomQueryFlag

        protected java.lang.Boolean checkCustomQueryFlag​(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                                 org.eclipse.persistence.internal.sessions.AbstractRecord translationRow)
        INTERNAL: Check and return custom query flag. Custom query flag value is initialized when stored value is null. Called from ObjectLevelReadQuery.checkForCustomQuery(AbstractSession, AbstractRecord) to retrieve custom query flag.
        Specified by:
        checkCustomQueryFlag in class ObjectLevelReadQuery
        Parameters:
        session - Current session (not used).
        translationRow - Database record (not used).
        Returns:
        Current custom query flag. Value will never be null.

      • clone

        public java.lang.Object clone()
        INTERNAL: Creates and returns a copy of this query.
        Overrides:
        clone in class ObjectLevelReadQuery
        Returns:
        A clone of this instance.

      • conformResult

        protected java.lang.Object conformResult​(java.lang.Object result,
                                         org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork,
                                         org.eclipse.persistence.internal.sessions.AbstractRecord arguments,
                                         boolean buildDirectlyFromRows)
        INTERNAL: Conform the result if specified.

      • execute

        public java.lang.Object execute​(org.eclipse.persistence.internal.sessions.AbstractSession session,
                                org.eclipse.persistence.internal.sessions.AbstractRecord row)
                         throws DatabaseException
        INTERNAL: Execute the query. If there are cached results return those. This must override the super to support result caching.
        Overrides:
        execute in class ObjectLevelReadQuery
        Parameters:
        session - - the session in which the receiver will be executed.
        Returns:
        An object or vector, the result of executing the query.
        Throws:
        DatabaseException - - an error has occurred on the database

      • executeObjectLevelReadQuery

        protected java.lang.Object executeObjectLevelReadQuery()
                                                throws DatabaseException
        INTERNAL: Execute the query. Get the rows and build the object from the rows.
        Specified by:
        executeObjectLevelReadQuery in class ObjectLevelReadQuery
        Returns:
        java.lang.Object collection of objects resulting from execution of query.
        Throws:
        DatabaseException - - an error has occurred on the database

      • extractRemoteResult

        public java.lang.Object extractRemoteResult​(org.eclipse.persistence.internal.sessions.remote.Transporter transporter)
        INTERNAL: Extract the correct query result from the transporter.
        Overrides:
        extractRemoteResult in class DatabaseQuery

      • getContainerPolicy

        public org.eclipse.persistence.internal.queries.ContainerPolicy getContainerPolicy()
        INTERNAL: Return the query's container policy.

      • getDefaultRedirector

        protected QueryRedirector getDefaultRedirector()
        INTERNAL: Returns the specific default redirector for this query type. There are numerous default query redirectors. See ClassDescriptor for their types.
        Overrides:
        getDefaultRedirector in class DatabaseQuery

      • getStartWithExpression

        public Expression getStartWithExpression()
        PUBLIC:
        Returns:
        Expression - the start with expression used to generated the hierarchical query clause in Oracle

      • getConnectByExpression

        public Expression getConnectByExpression()
        PUBLIC:
        Returns:
        Expression - the connect by expression used to generate the hierarchical query caluse in Oracle

      • getOrderSiblingsByExpressions

        public java.util.List<Expression> getOrderSiblingsByExpressions()
        PUBLIC:
        Returns:
        List<Expression> - the ordering expressions used to generate the hierarchical query clause in Oracle

      • getDirection

        public ReadAllQuery.Direction getDirection()
        PUBLIC:
        Returns:
        Direction - the direction in which the hierarchy is traversed

      • hasHierarchicalExpressions

        public boolean hasHierarchicalExpressions()
        INTERNAL: Verify that we have hierarchical query expressions

      • isDefaultPropertiesQuery

        public boolean isDefaultPropertiesQuery()
        INTERNAL: Return true if the query uses default properties. This is used to determine if this query is cacheable. i.e. does not use any properties that may conflict with another query with the same JPQL or selection criteria.
        Overrides:
        isDefaultPropertiesQuery in class ObjectLevelReadQuery

      • equals

        public boolean equals​(java.lang.Object object)
        INTERNAL: Return if the query is equal to the other. This is used to allow dynamic expression query SQL to be cached.
        Overrides:
        equals in class ObjectLevelReadQuery

      • isReadAllQuery

        public boolean isReadAllQuery()
        PUBLIC: Return if this is a read all query.
        Overrides:
        isReadAllQuery in class DatabaseQuery

      • prepareFromQuery

        public void prepareFromQuery​(DatabaseQuery query)
        INTERNAL: Prepare the query from the prepared query. This allows a dynamic query to prepare itself directly from a prepared query instance. This is used in the JPQL parse cache to allow preparsed queries to be used to prepare dynamic queries. This only copies over properties that are configured through JPQL.
        Overrides:
        prepareFromQuery in class ObjectLevelReadQuery

      • prepareSelectAllRows

        protected void prepareSelectAllRows()
        INTERNAL: Prepare the mechanism.

      • registerResultInUnitOfWork

        public java.lang.Object registerResultInUnitOfWork​(java.lang.Object result,
                                                   org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork,
                                                   org.eclipse.persistence.internal.sessions.AbstractRecord arguments,
                                                   boolean buildDirectlyFromRows)
        INTERNAL: All objects queried via a UnitOfWork get registered here. If the query went to the database.

        Involves registering the query result individually and in totality, and hence refreshing / conforming is done here.

        Specified by:
        registerResultInUnitOfWork in class ObjectLevelReadQuery
        Parameters:
        result - may be collection (read all) or an object (read one), or even a cursor. If in transaction the shared cache will be bypassed, meaning the result may not be originals from the parent but raw database rows.
        unitOfWork - the unitOfWork the result is being registered in.
        arguments - the original arguments/parameters passed to the query execution. Used by conforming
        buildDirectlyFromRows - If in transaction must construct a registered result from raw database rows.
        Returns:
        the final (conformed, refreshed, wrapped) UnitOfWork query result

      • registerResultSetInUnitOfWork

        public java.lang.Object registerResultSetInUnitOfWork​(java.sql.ResultSet resultSet,
                                                      java.util.Vector fields,
                                                      org.eclipse.persistence.internal.helper.DatabaseField[] fieldsArray,
                                                      org.eclipse.persistence.internal.sessions.UnitOfWorkImpl unitOfWork,
                                                      org.eclipse.persistence.internal.sessions.AbstractRecord arguments)
                                               throws java.sql.SQLException
        INTERNAL: Version of the previous method for ResultSet optimization.
        Returns:
        the final (conformed, refreshed, wrapped) UnitOfWork query result
        Throws:
        java.sql.SQLException

      • remoteExecute

        public java.lang.Object remoteExecute()
        INTERNAL: Execute the query through remote session.
        Overrides:
        remoteExecute in class DatabaseQuery

      • replaceValueHoldersIn

        public java.util.Map replaceValueHoldersIn​(java.lang.Object object,
                                           org.eclipse.persistence.internal.sessions.remote.RemoteSessionController controller)
        INTERNAL: replace the value holders in the specified result object(s)
        Overrides:
        replaceValueHoldersIn in class DatabaseQuery

      • setContainerPolicy

        public void setContainerPolicy​(org.eclipse.persistence.internal.queries.ContainerPolicy containerPolicy)
        PUBLIC: Set the container policy. Used to support different containers (e.g. Collections, Maps).

      • setHierarchicalQueryClause

        public void setHierarchicalQueryClause​(Expression startWith,
                                       Expression connectBy,
                                       java.util.List<Expression> orderSiblingsExpressions)
        PUBLIC: Set the Hierarchical Query Clause for the query

        Example:

        Expression startWith = builder.get("id").equal(Integer.valueOf(100)); //can be any expression which identifies a set of employees

        Expression connectBy = builder.get("managedEmployees"); //indicated the relationship that the hierarchy is based on, must be self-referential

        Vector orderBy = new Vector();

        orderBy.addElement(builder.get("startDate"));

        readAllQuery.setHierarchicalQueryClause(startWith, connectBy, orderBy);

        This query would generate SQL like this:

        SELECT * FROM EMPLOYEE START WITH ID=100 CONNECT BY PRIOR ID = MANAGER_ID ORDER SIBLINGS BY START_DATE

        Parameters:
        startWith - Describes the START WITH clause of the query - null if not needed
        connectBy - This should be a query key expression which indicates an attribute who's mapping describes the hierarchy
        orderSiblingsExpressions - Contains expressions which indicate fields to be included in the ORDER SIBLINGS BY clause - null if not required

      • setHierarchicalQueryClause

        public void setHierarchicalQueryClause​(Expression startWith,
                                       Expression connectBy,
                                       java.util.List<Expression> orderSiblingsExpressions,
                                       ReadAllQuery.Direction direction)
        PUBLIC: Set the Hierarchical Query Clause for the query, specifying the hierarchy traversal direction

        Example:

        Expression startWith = builder.get("id").equal(Integer.valueOf(100)); //can be any expression which identifies a set of employees
        Expression connectBy = builder.get("managedEmployees"); //indicated the relationship that the hierarchy is based on, must be self-referential
        Vector orderBy = new Vector();
        orderBy.addElement(builder.get("startDate"));
        readAllQuery.setHierarchicalQueryClause(startWith, connectBy, orderBy, Direction.CHILD_TO_PARENT);

        This query would generate SQL like this:

        SELECT * FROM EMPLOYEE START WITH ID=100 CONNECT BY ID = PRIOR MANAGER_ID ORDER SIBLINGS BY START_DATE

        Parameters:
        startWith - Describes the START WITH clause of the query - null if not needed
        connectBy - This should be a query key expression which indicates an attribute who's mapping describes the hierarchy
        orderSiblingsExpressions - Contains expressions which indicate fields to be included in the ORDER SIBLINGS BY clause - null if not required
        direction - The direction in which the hierarchy is traversed; if not specified, CHILD_TO_PARENT is used for OneToOne relationships and PARENT_TO_CHILD is used for collections

      • useCollectionClass

        public void useCollectionClass​(java.lang.Class concreteClass)
        PUBLIC: Configure the mapping to use an instance of the specified container class to hold the target objects.

        jdk1.2.x: The container class must implement (directly or indirectly) the Collection interface.

        jdk1.1.x: The container class must be a subclass of Vector.

      • useCursoredStream

        public void useCursoredStream()
        PUBLIC: Use a CursoredStream as the result collection. The initial read size is 10 and page size is 5.

      • useCursoredStream

        public void useCursoredStream​(int initialReadSize,
                              int pageSize)
        PUBLIC: Use a CursoredStream as the result collection.
        Parameters:
        initialReadSize - the initial number of objects to read
        pageSize - the number of objects to read when more objects are needed from the database

      • useCursoredStream

        public void useCursoredStream​(int initialReadSize,
                              int pageSize,
                              ValueReadQuery sizeQuery)
        PUBLIC: Use a CursoredStream as the result collection.
        Parameters:
        initialReadSize - the initial number of objects to read
        pageSize - the number of objects to read when more objects are needed from the database
        sizeQuery - a query that will return the size of the result set; this must be set if an expression is not used (i.e. custom SQL)

      • useMapClass

        public void useMapClass​(java.lang.Class concreteClass,
                        java.lang.String methodName)
        PUBLIC: Configure the query to use an instance of the specified container class to hold the result objects. The key used to index the value in the Map is the value returned by a call to the specified zero-argument method. The method must be implemented by the class (or a superclass) of the value to be inserted into the Map.

        jdk1.2.x: The container class must implement (directly or indirectly) the Map interface.

        jdk1.1.x: The container class must be a subclass of Hashtable.

        The referenceClass must set before calling this method.

      • useScrollableCursor

        public void useScrollableCursor()
        PUBLIC: Use a ScrollableCursor as the result collection.

      • useScrollableCursor

        public void useScrollableCursor​(int pageSize)
        PUBLIC: Use a ScrollableCursor as the result collection.
        Parameters:
        pageSize - the number of elements to be read into a the cursor when more elements are needed from the database.

      • useScrollableCursor

        public void useScrollableCursor​(ScrollableCursorPolicy policy)
        PUBLIC: Use a ScrollableCursor as the result collection.
        Parameters:
        policy - the scrollable cursor policy allows for additional result set options. Example:

        ScrollableCursorPolicy policy = new ScrollableCursorPolicy()

        policy.setResultSetType(ScrollableCursorPolicy.TYPE_SCROLL_INSENSITIVE);

        query.useScrollableCursor(policy);

      • supportsResultSetAccessOptimizationOnPrepare

        public boolean supportsResultSetAccessOptimizationOnPrepare()
        INTERNAL: Indicates whether the query can use ResultSet optimization. The method is called when the query is prepared, so it should refer only to the attributes that cannot be altered without re-preparing the query. If the query is a clone and the original has been already prepared this method will be called to set a (transient and therefore set to null) usesResultSetOptimization attribute.
        Overrides:
        supportsResultSetAccessOptimizationOnPrepare in class ObjectLevelReadQuery

      • supportsResultSetAccessOptimizationOnExecute

        public boolean supportsResultSetAccessOptimizationOnExecute()
        INTERNAL: Indicates whether the query can use ResultSet optimization. Note that the session must be already set. The method is called when the query is executed, so it should refer only to the attributes that can be altered without re-preparing the query.
        Overrides:
        supportsResultSetAccessOptimizationOnExecute in class ObjectLevelReadQuery