Result Sets
In the DB Interface Module paradigm, all results are tables. Class
RWDBTable encapsulates a single result set, class
RWDBResult encapsulates a sequence of 0 or more tables, and class
RWDBReader provides the mechanism for reading a table. Consequently, handling multiple result sets is not a problem.
In the DB Interface Module, the
execute() method of each DML class returns an
RWDBResult object. Applications that are concerned with results returned by an
INSERT, for example, can maintain portability between databases by checking the
RWDBResult returned by
RWDBInserter::execute().
Any data not processed by an application is silently discarded. The DB Interface Module applications need not explicitly discard results; they need not consider the state of the database connection.
Simultaneous Processing of Results from Multiple Statements Using the Same Connection
The PostgreSQL libpq API fetches the entire result of an execution to the client. Hence it is possible to execute multiple operations on a single connection and process their results simultaneously.