[hooks/syncschema] avoid altering a dropped table
If the constraint's rdef is being removed, CWConstraintDelOp doesn't
need to do anything. Otherwise it may try to alter a removed
table/column. Closes #4154549
config['rql-cache-size'] = config['rql-cache-size'] * 10
add_entity_type('CWDataImport')
from cubicweb.schema import CONSTRAINTS, guess_rrqlexpr_mainvars
for rqlcstr in rql('Any X,XT,XV WHERE X is CWConstraint, X cstrtype XT, X value XV,'
'X cstrtype XT, XT name IN ("RQLUniqueConstraint","RQLConstraint","RQLVocabularyConstraint"),'
'NOT X value ~= ";%"').entities():
expression = rqlcstr.value
mainvars = guess_rrqlexpr_mainvars(expression)
yamscstr = CONSTRAINTS[rqlcstr.type](expression, mainvars)
rqlcstr.cw_set(value=yamscstr.serialize())
print 'updated', rqlcstr.type, rqlcstr.value.strip()