Question

我想在mysql中执行一个爆炸式的任务，我需要在每天从开始和结束日期创建新记录。

目前的数据如下：

Person, Start Date, End Date, Score
a     , 12/05/2017, 14/05/2017, 0.8
a     , 15/05/2017, 17/07/2017, 0.3
b     , 12/05/2017, 14/05/2017, 0.5
b     , 15/05/2017, 17/07/2017, 0.2

现在，我需要重新创建数据

Person, Date,  Score
a     , 12/05/2017, 0.8
a     , 13/05/2017, 0.8
a     , 14/05/2017, 0.8
a     , 15/05/2017, 0.3
a     , 16/05/2017, 0.3
a     , 17/05/2017, 0.3
b     , 12/05/2017, 0.5
b     , 13/05/2017, 0.5
b     , 14/05/2017, 0.5
b     , 15/05/2017, 0.2
b     , 16/05/2017, 0.2
b     , 17/05/2017, 0.2

因为，我将此表与其他表格一起加入日期和时间表。 person列，需要此操作。我怎么能在MySQL中做到这一点？

Answer 1

您可以使用以下查询来获得结果 -

create table PersonTable (
 Person varchar(10), StartDate   date   , EndDate date, Score float
)
go


insert into PersonTable   
select 'a'     , '2017-05-12', '2017-05-14', 0.8
union all select 'a'     , '2017-05-15', '2017-07-17', 0.3
union all select 'b'     , '2017-05-12', '2017-05-14', 0.5
union all select 'b'     , '2017-05-15', '2017-07-17', 0.2

create table #DateList (Date_Time date)

declare @MinDt Date , @MaxDt Date

select @MinDt=  Min(StartDate) , @MaxDt = Max(EndDate) from  PersonTable
while (@MinDt < = @MaxDt)
begin
 insert into #DateList
 select @MinDt 
 select  @MinDt =  dateadd(day,1, @MinDt) 
end  

select t1.Person , t2.Date_Time , t1.Score from PersonTable t1
join #DateList t2 on 
t1.StartDate <= t2.Date_Time
and t1.EndDate >=t2.Date_Time

Answer 2

此代码适用于SQL SERVER中的上述问题

create table  TempTable      -------Creating table 
(
Person varchar(20),
[Date] date ,
Score float
)


Declare @person varchar(20),@StartDate date,@Enddate date,@Score float,@temp int = 1,@count int ;                 -----------Local variable declaring

select @count = count(*) from <YourTableName>      ------Row count

while ( @count > 0)
begin

with CTE_Select
as
(
select row_number() over (order by Person) id,  * from [dbo].[difference_table]
)
select @person = Person,@StartDate = [Start_date],@Enddate = End_date,@Score = Score from CTE_Select
where id = @temp               -------------Taking first Row

Declare @diff int = datediff(dd,@StartDate,@Enddate)
while (@diff > 0 )
begin
insert into temptable (Person,[Date],Score)
select @person,@StartDate,@Score 
set @StartDate = DATEADD(dd,1,@StartDate)
Set @diff = @diff - 1
end
set @temp = @temp + 1                         ---------------selecting next row
set @count = @count - 1                       ---------------decreasing row count
end ;
select * from TempTable;                     ------------Select modified table

SQL - 将范围之间的日期作为新记录进行分解

2 个答案: