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: Connection information for open database connections is stored or “cached” in a connection manager at the database client. Therefore, even when a query is complete and the connection between the client and server is released, the manager maintains the database connection open. When a new query arrives at the client, the connection manager compares the connection information in the query to the corresponding information stored for each open connection. If there is a match and the connection is not in use, the already open connection is used for the new query. If there is no match, a new connection is opened until a predetermined limit of the number of connections is reached. When the limit is reached, an open connection which is not in use is closed and a new connection is established. In accordance with a preferred embodiment, a “free” list of open connections which are not in use is maintained so that a quick comparison can be made with the incoming query information.