Re: [Sqlalchemy-tickets] [sqlalchemy] #2501: the DELETE before INSERT problem

[sqlalchemy <mi...@zz...>]

#2501: the DELETE before INSERT problem
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      Reporter:  zzzeek       |      Owner:  zzzeek
          Type:  defect       |     Status:  new
      Priority:  high         |  Milestone:  0.9.xx
     Component:  orm          |   Severity:  very major - up to 2 days
    Resolution:               |   Keywords:
Progress State:  needs tests  |
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Comment (by schlamar):

 Another update: there are some issues with association proxy handling and
 doing flush when the object is not yet fully created (similar to #2809).
 So here is a fixed version for the code above:


 {{{
 #!python

 def fix_order_by_constraint(session, obj, field, value):
     setattr(obj, field, list())
     session.flush()  # possibly trigger delete cascade
     for v in value:
         state = inspection.inspect(v)
         if state.deleted:
             orm.make_transient(v)  # put it back to life

             # reset order by fields
             for attr in get_order_by_properties(type(obj), field):
                 if hasattr(v, attr):
                     setattr(v, attr, None)


 value = [get_related_obj(session, obj, v, field) for v in value]
 if obj.id:
     fix_order_by_constraint(session, obj, field, value)
 setattr(obj, field, value)
 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2501#comment:15>
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