In the reverse engineering process, Hibernate Tools is missing many-to-one relationships in which foreign key references a unique key in the one side.

Here is a test case: table detail has a foreign key to table master, and references a column that has a unique constraint (uk_master).

Now, when executing Hibernate Tools with OracleMetaDataDialect, this relationship is not captured by the metadata query issued by OracleMetaDataDialect (constant SQL_FK_BASE). This is so because OracleMetaDataDialect is restricting foreign key relationships only to primary key constraints:

If we change this restriction so that it includes also unique key constraints, it works:

As far as I know, this change doesn't have side effects.

There is a patch attached.

(If you need, I can zip a simple maven project with this test case.)