[migration] don't attempt to carry over values when renaming a computed relation
Without the fix in migractions.py, the introduced test crashes with an
operational error because of an attempt to write to a non-existing
relation table (computed relations are not materialized).
Closes #6304946
# copyright 2014 LOGILAB S.A. (Paris, FRANCE), all rights reserved.# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr## This file is part of CubicWeb.## CubicWeb is free software: you can redistribute it and/or modify it under the# terms of the GNU Lesser General Public License as published by the Free# Software Foundation, either version 2.1 of the License, or (at your option)# any later version.## CubicWeb is distributed in the hope that it will be useful, but WITHOUT# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more# details.## You should have received a copy of the GNU Lesser General Public License along# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.fromyams.buildobjsimport(EntityType,RelationDefinition,ComputedRelation,Int,Float)classEmployee(EntityType):passclassemployees(RelationDefinition):subject='Company'object='Employee'classassociates(RelationDefinition):subject='Company'object='Employee'classworks_for(ComputedRelation):rule='O employees S, NOT EXISTS (O associates S)'classCompany(EntityType):score=Float(formula='Any AVG(NN) WHERE X employees E, N concerns E, N note NN')score100=Float(formula='Any AVG(NN) WHERE X employees E, N concerns E, N note100 NN')classNote(EntityType):note=Int()note100=Int(formula='Any N*100 WHERE X note N')classconcerns(RelationDefinition):subject='Note'object='Employee'classwhatever(ComputedRelation):rule='S employees E, O associates E'classrenamed(ComputedRelation):rule='S employees E, O concerns E'