elements.py 文件源码

def _gen_label(self, name):
        t = self.table

        if self.is_literal:
            return None

        elif t is not None and t.named_with_column:
            if getattr(t, 'schema', None):
                label = t.schema.replace('.', '_') + "_" + \
                    t.name + "_" + name
            else:
                label = t.name + "_" + name

            # propagate name quoting rules for labels.
            if getattr(name, "quote", None) is not None:
                if isinstance(label, quoted_name):
                    label.quote = name.quote
                else:
                    label = quoted_name(label, name.quote)
            elif getattr(t.name, "quote", None) is not None:
                # can't get this situation to occur, so let's
                # assert false on it for now
                assert not isinstance(label, quoted_name)
                label = quoted_name(label, t.name.quote)

            # ensure the label name doesn't conflict with that
            # of an existing column
            if label in t.c:
                _label = label
                counter = 1
                while _label in t.c:
                    _label = label + "_" + str(counter)
                    counter += 1
                label = _label

            return _as_truncated(label)

        else:
            return name