[Hibernate] Implentation of Outer Join for Oracle

[Jon L. <jon...@xe...>]

Hi Gavin,

I finally have time try to add the Oracle joins stuff into the new =
refactored version of Hibernate in CVS.

I want to run my ideas by you before I do them, to make sure you agree =
(and to make sure I understand your refactorings correctly :-)

1) Refactor the outer join generation into a seperate class so that the =
current OuterJoinLoader calls a seperate class to actually create the =
SQL statement fragments.

2) Add the ability for a dialect to specify which OuterJoinGenerator to =
use.

3) Add an OracleOuterJoinGenerator (based on the code I've already =
written for the 1.1 version of Hibernate).

4) Modify OuterJoinLoader so that it has two possible places it can add =
to the SQL statement. ie.. After the FROM part of the SQL is generated =
and after the WHERE clause.  So, for example, in the CollectionLoader, =
when it is generating the SQL, it would do something like:

  sql =3D sqlSelect(
   // SELECT CLAUSE
   selectCollectionString(persister, alias) +
   ( joins=3D=3D0 ? "" : ", " + selectString(associations) ),
   // FROM CLAUSE
   persister.getQualifiedTableName()+' '+alias,
   // OUTER JOINS PART 1
   outerJoinStringAfterFrom(associations),
   // WHERE CLAUSE
   whereString( persister.getKeyColumnNames(), alias ),
   // OUTER JOINS PART 2
   outerJoinStringAfterWhere(associations),
   // ORDER BY CLAUSE
   ( persister.hasOrdering() ) ?
    alias + '.' + persister.getSQLOrderByString() :
    null
  );

What do you think of that idea?  Doing it this way wouldn't require the =
addition of an Environment variable like my previous solution, and it =
would allow us to add other outer join strategies if needed.

Jon...