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The download package comes with several pre-installed drivers. Look in <frevvo-home>/tomcat/lib and you will see (among other jar files) the following pre-installed driver jar files:
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For example the HSQLDB.jar file is located in WEB-INF/lib in the frevvo.war.
If you don't find what you need pre-installed you will need to locate a driver compatible to your database. Usually you can download your driver from the internet. Try one of these locations
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