base.py 文件源码

def visit_extract(self, extract, **kw):
        try:
            return "CAST(STRFTIME('%s', %s) AS INTEGER)" % (
                self.extract_map[extract.field],
                self.process(extract.expr, **kw)
            )
        except KeyError:
            raise exc.CompileError(
                "%s is not a valid extract argument." % extract.field)