Re: [Sqlalchemy-tickets] [sqlalchemy] #2721: SQLAlchemy leaks the deferrable keyword in FKs for mysql databases

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

#2721: SQLAlchemy leaks the deferrable keyword in FKs for mysql databases
---------------------------+----------------------------------
      Reporter:  kashif    |      Owner:
          Type:  defect    |     Status:  new
      Priority:  medium    |  Milestone:  0.8.xx
     Component:  mysql     |   Severity:  minor - half an hour
    Resolution:            |   Keywords:  mysql deferrable
Progress State:  in queue  |
---------------------------+----------------------------------
Changes (by zzzeek):

 * priority:  high => medium


Comment:

 oh also here's a workaround for you, just override
 visit_foreign_key_constraint, should work in 0.7 too:

 {{{
 from sqlalchemy.schema import ForeignKeyConstraint
 from sqlalchemy.ext.compiler import compiles

 @compiles(ForeignKeyConstraint, "mysql")
 def visit_foreign_key_constraint(element, compiler, **kw):
     deferrable = getattr(element, "deferrable", None)
     if deferrable is True:
         element.deferrable = None
     text = compiler.visit_foreign_key_constraint(element, **kw)
     if deferrable is True:
         element.deferrable = True
     return text

 if __name__ == '__main__':
     from sqlalchemy import MetaData, Column, Table, create_engine,
 ForeignKey, Integer

     m = MetaData()

     t1 = Table('t1', m, Column('id', Integer, primary_key=True))
     t2 = Table('t2', m, Column('id', Integer, ForeignKey('t2.id',
 deferrable=True), primary_key=True))

     e1 = create_engine("postgresql://scott:tiger@localhost/test",
 echo=True)
     e2 = create_engine("mysql://scott:tiger@localhost/test", echo=True)

     m.create_all(e1)
     m.create_all(e2)

     m.drop_all(e1)
     m.drop_all(e2)


 }}}

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Ticket URL: <http://www.sqlalchemy.org/trac/ticket/2721#comment:5>
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