SELECT DATE_FORMAT(FROM_UNIXTIME(`pd`.`pdet_create_time`), "%m-%d") AS `days`,
                SUM(`pd`.`pdet_money`) AS `sum`
        FROM `web_payment_details` AS `pd`

        LEFT JOIN `web_user`   AS `user`   ON `user`.`use_id` = `pd`.`use_id`
        LEFT JOIN `web_use_invite` AS `use_invite` ON `use_invite`.`use_id` = `pd`.`use_id`

        WHERE `user`.`use_auto_reg`=0
        AND `pd`.`pdet_type` = 1 # 任务完成条件
        AND TO_DAYS(FROM_UNIXTIME(`pd`.`pdet_create_time`)) <= TO_DAYS(FROM_UNIXTIME(`user`.`use_regtime`+(86400*7)))
        AND `pd`.`pdet_create_time` >= 1449244800
        GROUP BY `pd`.`use_id`
        
        
        
        EXPLAIN的结果：
        

1    SIMPLE    pd    ref    index_ui_pi_pt,pt    pt    1    const    70155    Using where; Using temporary; Using filesort
            
1    SIMPLE    user    eq_ref    PRIMARY    PRIMARY    4    wan.pd.use_id    1    Using where

1    SIMPLE    use_invite    ref    use_id    use_id    4    wan.pd.use_id    1    Using index