dal.py 文件源码

def _create_references(self):
        db = self._db
        pr = db._pending_references
        self._referenced_by = []
        for field in self:
            fieldname = field.name
            field_type = field.type
            if isinstance(field_type,str) and field_type[:10] == 'reference ':
                ref = field_type[10:].strip()
                if not ref.split():
                    raise SyntaxError('Table: reference to nothing: %s' %ref)
                refs = ref.split('.')
                rtablename = refs[0]
                if not rtablename in db:
                    pr[rtablename] = pr.get(rtablename,[]) + [field]
                    continue
                rtable = db[rtablename]
                if len(refs)==2:
                    rfieldname = refs[1]
                    if not hasattr(rtable,'_primarykey'):
                        raise SyntaxError(
                            'keyed tables can only reference other keyed tables (for now)')
                    if rfieldname not in rtable.fields:
                        raise SyntaxError(
                            "invalid field '%s' for referenced table '%s' in table '%s'" \
                            % (rfieldname, rtablename, self._tablename))
                rtable._referenced_by.append(field)
        for referee in pr.get(self._tablename,[]):
            self._referenced_by.append(referee)