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The query builders in HID web app use strategy design pattern to separate
invariant part of SQL query building from variant part. The variant part is provided
by the implementations of ISQLDialect interface. The query builders only interact
with ISQLDialect interface, while the factory method in ServiceFactory
classes is responsible to provide an apropriate implementation depending on the DBMS type
(currently either OracleSQLDialect or PostgresSQLDialect). For new complex
query building tasks for which single table mapped DAOs are inefficient and/or inadequate,
you should be using this mechanism to cope with DBMS supported SQL language differences.
Burak Ozyurt
2008-03-28