This patch implements the "date" function for the OracleDialect and fixes the "hour", "minute" and "second" functions for DATE columns. These are needed for the various DateTime properties when used in Linq queries.
Note: "extract" is not officially supported before Oracle 9, but I've read some reports that it works in Oracle 8 too. And since I couldn't find a different way to do it in Oracle 8 I've included them all in the Oracle8iDialect. Even if it doesn't work it won't break more than without them.