这是我需要从db中获取连续数据的保留查询我已经用两个表写了这个查询
sessions - deviceid，start_time
选择
u.DayOffset as Date，
SUM（s.DayOffset = 0）AS d0，
SUM（s.DayOffset = 1）AS d1，
SUM（s.DayOffset = 2）AS d2，
SUM（s.DayOffset = 3）AS d3
FROM
（SELECT id，DATE（created_at）AS DayOffset FROM deviceinfodatas WHERE created_at BETWEEN'2017-10-01'''2017-12-30'）as u LEFT JOIN
（SELECT DISTINCT sessions.deviceid， DATEDIFF（DATE（sessions.start_time），DATE（deviceinfodatas.created_at）） AS DayOffset FROM sessions
LEFT JOIN deviceinfodatas ON（deviceinfodatas.id = sessions.deviceid）WHERE sessions.start_time BETWEEN'2017-10-01'和'2017-12-30'） as s ON s.deviceid = u.id GROUP BY u.DayOffset
我的结果是
Date d0 d1 d2 d3
2017-10-25 1 0 0 0
2017-10-27 1 0 0 0
2017-10-31 0 0 1 1
2017-11-02 1 0 0 0
2017-11-03 1 0 0 0
2017-11-06 1 0 0 0
2017-11-08 1 0 0 0
2017-11-09 0 0 1 0
2017-11-13 0 0 1 0
2017-11-16 5 1 0 0
但我需要一个连续的约会
as
Date d0 d1 d2 d3
2017-10-25 1 0 0 0
2017-10-26 0 0 0 0
2017-10-27 1 0 0 0
2017-10-28 0 0 0 0
2017-10-29 0 0 0 0
2017-10-30 0 0 0 0
2017-10-31 0 0 1 1
.....
2017-11-16 5 1 0 0
并且还根据日期范围计算日d0，d1，d2，d3，d4，d5 ...... dn必须动态增加
我是Mysql的初学者，请帮助这个查询来实现我的结果
我引用了Continuous date和Daily retention query
提前谢谢
答案 0 :(得分：0)
如果要返回日期值，则查询将需要日期值的行源。这可以是填充了您需要返回的所有日期值的日历表cal，也可以是动态返回日期集的内联视图。
包含唯一值的简单日历表的示例。这个表需要维护，我们需要确保它包含我们想要返回的所有可能的日期值，没有间隙。
CREATE TABLE cal (dt DATE NOT NULL PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO cal (dt) VALUES ('2017-10-01'),('2017-10-02'),('2017-10-03') ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 3 DAY FROM cal ORDER BY dt ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 6 DAY FROM cal ORDER BY dt ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 12 DAY FROM cal ORDER BY dt ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 24 DAY FROM cal ORDER BY dt ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 48 DAY FROM cal ORDER BY dt ;
INSERT INTO cal (dt) SELECT dt + INTERVAL 96 DAY FROM cal ORDER BY dt ;
然后我们可以这样做：
SELECT c.dt
, ...
FROM cal c
LEFT
JOIN mytable t
ON t.date_col = c.dt
WHERE c.dt >= '2017-10-25'
AND c.dt < '2017-10-25' + INTERVAL 30 DAY
答案 1 :(得分：0)
这是工作查询
如果不创建单独的表格，很容易获得连续日期
这可能有助于某人！
UIBezierPath *maskPath = [UIBezierPath
bezierPathWithRoundedRect:ViewSwapMyWork.bounds
byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight)
cornerRadii:CGSizeMake(70, 70)
];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = ViewSwapMyWork.bounds;
maskLayer.path = maskPath.CGPath;
ViewSwapMyWork.layer.mask = maskLayer;
结果如下
SELECT u.DayOffset as Date,
COALESCE(SUM(s.DayOffset = 0),0) AS d0,
COALESCE(SUM(s.DayOffset = 1),0) AS d1,
COALESCE(SUM(s.DayOffset = 2),0) AS d2,
COALESCE(SUM(s.DayOffset = 3),0) AS d3,
COALESCE(SUM(s.DayOffset = 4),0) AS d4,
COALESCE(SUM(s.DayOffset = 5),0) AS d5,
COALESCE(SUM(s.DayOffset = 6),0) AS d6,
COALESCE(SUM(s.DayOffset = 7),0) AS d7,
COALESCE(SUM(s.DayOffset = 8),0) AS d8,
COALESCE(SUM(s.DayOffset = 9),0) AS d9
FROM ( SELECT id, DATE(d.created_at) AS DayOffset from
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 +
t0.i) `created_at` from
(select 0 i union select 1 union select 2 union select 3 union select 4
union select 5 union select 6 union select 7 union select 8 union select 9)
t0,
(select 0 i union select 1 union select 2 union select 3 union select 4
union
select 5 union select 6 union select 7 union select 8 union select 9) t1,
(select 0 i union select 1 union select 2 union select 3 union select 4
union select 5 union select 6 union select 7 union select 8 union select 9)
t2,
(select 0 i union select 1 union select 2 union select 3 union select 4
union select 5 union select 6 union select 7 union select 8 union select 9)
t3,
(select 0 i union select 1 union select 2 union select 3 union select 4
union select 5 union select 6 union select 7 union select 8 union select 9)
t4) d
left join deviceinfodatas v on DATE(d.`created_at`) = DATE(v.`created_at`)
where DATE(d.`created_at`) between '2017-11-01' and '2017-11-11') as u
LEFT JOIN ( SELECT DISTINCT sessions.deviceid,
DATEDIFF(DATE(sessions.start_time), DATE(deviceinfodatas.created_at))
AS DayOffset FROM sessions
LEFT JOIN deviceinfodatas ON (deviceinfodatas.id = sessions.deviceid) WHERE
sessions.start_time BETWEEN '2017-11-01' AND '2017-11-11' )
as s ON s.deviceid = u.id GROUP BY u.DayOffset
我可以实现连续约会但仍在努力获得日数d0，d1，...... d12
我正在尝试在php mysql中我在php中尝试使用查询中的日期差异计数，如果有任何提示将被赞赏
谢谢