在mysql中显示所有日期甚至没有数据[重复]答案

【问题标题】：Display all dates even no data in mysql [duplicate]在mysql中显示所有日期甚至没有数据[重复]
【发布时间】：2019-05-24 11:50:56
【问题描述】：

我有一个问题，

select value, updateddate from valid_table where date(updateddate) between '2018-11-01' and '2018-11-07';

value date
40    2018-11-01
50    2018-11-03
70    2018-11-05

但我想显示所有日期，即使没有特定日期的数据，如下所示，

value date
40    2018-11-01
0     2018-11-02
50    2018-11-03
0     2018-11-04
70    2018-11-05
0     2018-11-06
0     2018-11-07

注意：开始和结束日期可能是 2018-10-01 和 2018-12-01

如何做到这一点？

【问题讨论】：

你的mysql版本是多少？
@fa06 版本为 5.5
看看这个dba.stackexchange.com/a/179375
考虑处理应用代码中数据显示的问题

标签： mysql sql

【解决方案1】：

要获取开始日期和结束日期之间的日期，您可以使用以下查询。希望这可以帮到你。要从表中获取此结果，您可以使用联接。

select * from 
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date 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) v
where selected_date between '2012-02-10' and '2012-02-15'

【讨论】：

【解决方案2】：

你可以试试下面的左连接

 select tdate, coalesce(value,0) as value from 
    (select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) tdate 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) t1
    left join valid_table on t1.tdate= updateddate 
    where tdate between '2012-02-10' and '2012-02-15'

【讨论】：