sql 找错，一个很奇怪的错误

        sql = "UPDATE bs2_dl_road_min SET count=count+{0} WHERE time='{1}' "\
            "AND host_ip='{2}' AND module='{3}' AND method='{4}' AND status='{5}' "\
            "AND size_level='{6}' AND level='{7}' AND submodule_road='{8}'".format(count, \
            str_time, host_ip, module, method, status, size_level, level, submodule_road)
        if db.myCur.execute(sql) >= 1:
            return True
    except Exception, e:
        #logger.error(traceback.format_exc().replace('\n', ' '))
        return False
    finally:
        db.myConn.commit()

    ############################ Insert
    try:           
        sql = "INSERT INTO bs2_dl_road_min(region, zone_id, host_ip, module, method, "\
            "status, size_level, level, submodule_road, count, time) "\
            "VALUES('{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', '{7}', '{8}', '{9}', "\
            "'{10}')".format(region, zone_id, host_ip, module, method, status, \
            size_level, level, submodule_road, count, str_time)
        if db.myCur.execute(sql) >= 1:
            return True
    except Exception, e:
        #logger.error(traceback.format_exc().replace('\n', ' '))
        return False
    finally:
        db.myConn.commit()

    ############################ Update
    try:
        sql = "UPDATE bs2_dl_road_min SET count=count+{0} WHERE time='{1}' "\
            "AND host_ip='{2}' AND module='{3}' AND method='{4}' AND status='{5}' "\
            "AND size_level='{6}' AND level='{7}' AND submodule_road='{8}'".format(count, \
            str_time, host_ip, module, method, status, size_level, level, submodule_road)
        if db.myCur.execute(sql) >= 1:
            return True
    except Exception, e:
        #logger.error(traceback.format_exc().replace('\n', ' '))
        return False
    finally:
        db.myConn.commit()

                    三段sql ，逻辑是第一段根据主键更新数据，如果更新失败，说明主键不存在，则用此主键插入数据。如果插入失败，说明可能此主键被别的线程的事务插入了，再一次执行第一步的更新动作，这个程序跑了至少一年，都没出过问题
                    现在问题是，三段都出错了，第一段返回0，第二段直接报错主键冲突，第三段又返回0，求高手指导可能的问题在哪

关键你这个不是纯 sql，建议你调试下看看呢