33def downgrade():
   34    yesno_values = ENUM(*YESNO_VALUES, name=YESNO_NAME, create_type=False)
   35    if op.get_context().bind.dialect.name != 'mssql':
   36        op.alter_column('ps_transports', 'verify_server', type_=yesno_values,
   37                        new_column_name='verifiy_server')
   38    else:
   39        op.alter_column('ps_transports', 'verify_server', existing_type=yesno_values, type_=sa.String(3),
   40                        new_column_name='verifiy_server')
   41        yesno_values = ENUM(*YESNO_VALUES, name=YESNO_NAME, create_type=True)
   42        op.alter_column('ps_transports', 'verifiy_server', existing_type=sa.String(3), type_=yesno_values)