SQLAlchemy:如何按两个字段分组和按日期筛选

以下内容应将您指向正确的方向,另请参见内联注释:

qry = (session.query(
                table.c.field1,
                table.c.field2,
                # #strftime* for year-month works on sqlite; 
                # @todo: find proper function for mysql (as in the question)
                # Also it is not clear if only MONTH part is enough, so that
                # May-2001 and May-2009 can be joined, or YEAR-MONTH must be used
                func.strftime('%Y-%m', table.c.datestamp),
                func.count(),
                )
        # optionally check only last 2 month data (could have partial months)
        .filter(table.c.datestamp < datetime.date.today() - datetime.timedelta(60))
        .group_by(
                table.c.field1,
                table.c.field2,
                func.strftime('%Y-%m', table.c.datestamp),
                )
        # comment this line out to see all the groups
        .having(func.count()>1)
      )