Select object needs copy_container()

[Mike Bayer]

some compilation/mapper steps want to take an incoming Select statement and modify it before compiling/continuing compilation. Particularly for some tweaks in the Oracle module where it makes life a lot easier to modify the Select and send it down to the base ansisql module, rather than re-implementing all of visit_select().

The point is, when it wants to modify a select it should be creating a copy of the select and operating upon that, so that the original is untouched. So we need copy_container() fully implemented on the select object (and also CompoundSelect)....and it should run fast !

[Mike Bayer]

additionally, some tests in test/sql to ensure that the copied selectable produces identical sql to its original.

this is not a hard ticket at all but just requires some completeness.

[Mike Bayer]

this feature is also needed in order to allow ClauseAdapter to work with Select objects, i.e. blocks #569.

[Mike Bayer]

changeset:2777

[Mike Bayer]

Removing milestone: 0.4.0 (automated comment)