The system, method, and program of this invention enables an object language application to issue a query over a view and to receive back, as query results, handles to application type objects which can be further manipulated by the application. A view is defined herein as a collection of a view type, and a view type is defined as a class or type. Upon receipt of the query referencing a view type, a query engine generates a query plan that builds mock (i.e., proxy) application type objects in memory based upon the view types. The application objects have a form that is consistent with the class definition for a type of object returned as a result. The application can run methods on the application type objects or point to other application type objects from the handles, to the application objects, that are returned to the application; and these manipulations will be understood by the query engine. In a preferred embodiment, query rewrite optimizations are applied to the queries over views requiring object building in order to optimize the evaluation of the query and the building of view objects as query results.
CROSS REFERENCE TO RELATED APPLICATION
This application is related by common inventorship and subject matter to copending U.S. patent application Ser. No. 08/853,294 (Internal Docket Number ST9-97-071) entitled "A System, Method, and Program for Applying Query Rewrite Technology to Object Building," filed on even date herewith by Michael J. Carey, et al., assigned to the Assignee hereof and entirely incorporated herein by this reference.
This application is related by subject matter to copending U.S. patent application Ser. No. 08/853,270 (Internal Docket Number ST9-97-052) entitled "Optimized Caching of SQL Data In An Object Server System" filed on even date herewith by Gopi K. Attaluri et al., assigned to the Assignee hereof and entirely incorporated herein by this reference.
A portion of the disclosure of this patent document contains material which
is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
One embodiment of the present invention provides a method for constructing a query for an object-relational database. This method displays at least part of a schema for the object-relational database to a user in a graphical representation. Next, the method allows the user to perform graphical manipulations on the schema. The method then generates a query based upon the schema and the graphical manipulations, and this query is sent to the object-relational database. Another embodiment of the present invention provides a method for processing an object-relational query for transmission from a client to an object-relational database server. This method receives the query at the client, and parses the query to determine which object-relational structures the query is attempting to access. The method then determines from data dictionary information, loaded from the object-relational database server and cached locally on the client, if the object-relational structures the query is attempting to access exist in the object-relational database server. If they do not exist, the method indicates an error condition. Yet another embodiment of the present invention provides a method for displaying objects defined within an object-oriented programming system that are stored in a relational table structure. This method displays a table of objects, so that a first object in the table is represented by an identifier. The method next receives a command from a user to provide a more-detailed display of the first object. In response to this command, the method retrieves attributes of the first object from a data store, and displays an expanded representation of the first object by displaying the attributes.
There is provided a system and method for representing a data subset of server data. According to the method, a folder definition is generated for the data subset. The generation of the folder definition includes the substeps of identifying portions of the server data to be included in the data subset, generating declarations of value constraints and usage constraints with respect to at least some of the data of the data subset, and generating parameters to be supplied or selected by a user of a client device for further identifying the portions of the server data to be included in the data subset. The declarations are used for enforcing the value constraints and the usage constraints in subsequent renderings of the data subset on a client device. A folder instance is then generated based on the folder definition and parameters provided by a user of a client device or by default. The provided parameters (user provided or default) correspond to the generated parameters. The generation of the folder instance includes the substeps of generating the data subset from the identified portions of the server data and the parameters, and including the declarations of value constraints and usage constraints in the folder instance with the data subset.
A data storage and retrieval system includes a data space area where a set of data belonging to a predetermined category and definition data describing definition of the structure and the presentation form of the data are stored, a data space retrieval section for retrieving data and definition data made to correspond to the data from the data space area, a data space operation section for rewriting the definition data made to correspond to the data retrieved by the retrieval section on the basis of another definition data stored in the data space area, and a display for displaying the data retrieved by the retrieval section on the basis of the definition data rewritten by the operation section.
A method for manipulating objects within a distributed object oriented environment on a data processing system. Complex issues of a distributed object oriented environment are encapsulated within a software generated framework. A plurality of abstract classes of objects with predefined characteristics is created for utilization within the framework. Also, a plurality of proxy objects are connected to the framework. The framework manipulates the proxy objects to instantiate communication and data transfer between objects of the distributed object oriented environment.
A schema-isolated system is disclosed for developing, modifying, or maintaining client applications that accesses target databases. The system includes a middleware-table inserter that inserts middleware tables into the target database. The middleware tables include a set of compatibility data relating one or more client-application data requests with one or more corresponding target-database data capabilities. The middleware tables also include a data communication component. This component receives a client-application data request from the client application, and, based on at least a first datum of the set of compatibility data, provides to the client application the one or more target-database data capabilities corresponding to the client-application data request. The first compatibility datum relates the one or more client-application data requests with the one or more corresponding target-database data capabilities based, at least in part, on an application-usage-independent criterion. An application-usage-independent criterion may be a syntax criterion, a configuration criterion, or a component-usage criterion. The first compatibility datum may include at least one SQL query. The at least one target database may be a relational database.
