Abstract: A query object generator tool which generates interface definitions and code that implement a query object also generates a database schema access query object that retrieves the schema of an underlying database. Instead of retrieving data from the database, the database schema access query object retrieves “metadata”, including the names of tables and stored procedures in the database and their descriptions, from the database. The metadata is then displayed as part of a graphic user interface which is used to construct the SQL query implemented by the query object. In accordance with one embodiment of the invention, the database schema access object also verifies that an SQL query generated by a user is valid by submitting the query to the database engine of the underlying database. In accordance with another embodiment of the invention the database schema access object contains methods which perform automatic mapping of “standard” SQL data types to vendor-specific data.

Abstract: A query object generator tool is used to generate interface definitions and source code which implement a database query object. The tool allows a client to construct a query object without being familiar with the underlying database language and without being concerned with programming details such as concurrency problems and connection management. The tool consists of an internal state object which represents the query object, including information which can be saved to reconstruct the query object at a later date, and code generator objects which generate the code required to implement the query object defined by the internal state object. In a preferred embodiment, the code generator objects are arranged in a hierarchy so that a generator object can be instantiated which generator object is specific to the database to be accessed and the language to which the implementation is targeted. An optional graphic user interface (GUI) may also be provided to allow a user to interact with the tool.

Abstract: A query object generator tool which generates interface definitions and code that implement a query object also generates a graphic user interface (GUI) for controlling the generator tool and plug-in objects, including a database schema access query object and test objects for allowing the GUI to operate with vendor-specific databases. The GUI is “customized” by the various plug-in objects. For example, the database schema access query object is designed specifically for a particular underlying database and retrieves “metadata” concerning the database schema. The retrieved metadata is then displayed as part of the graphic user interface to assist the user in constructing a query object. Test objects are also generated by the GUI in response to a user request. The test objects contain information that characterizes the query object for testing purposes. The information in the test objects is used with a test framework to install and initialize the query object.