Oracle expects values for every parameter, even if the same parameter occurs twice

[stackwave]

The existing NamedValueGatherer will skip parameters it has already seen. However, Oracle expects a value to be supplied for every parameter, even if that parameter occurs twice. As an example:

SELECT * FROM foo WHERE foo.a = :t0 AND foo.b = :t1 AND foo.c = :t0

One would expect that supplying exactly two parameters for :t0 and :t1 would be sufficient, but for Oracle, this is incorrect. Three parameters must be supplied, for :t0, :t1, and then :t0 again.

I introduced an if/else statement in SubSonic.Linq.Structure.ExecutionBuilder that checked whether the language being used was the OracleLanguage, and if so, used a special OracleNamedValueGatherer that paired every parameter name with its corresponding value regardless of whether it had already been seen. However, this may not be the most SubSonic-y way of doing things.