How to Create table with Dates in range defined by table with start date inputs

Question

I am trying to create a dates table in SQL based on a set of inputs, but I haven't been able to figure it out.

I am receiving in SQL inputs as below:

This table:

Date	Value
2022-01-01	5
2022-07-12	10
2022-11-15	3

A Start Date = 2022-01-01 A stop Date = 2022-12-01

I need to get a table as below starting from Start Date until Stop Date, assiging each correspondent number based on the initial table to each date in that period:

Date	Value
2022-01-01	5
2022-01-02	5
2022-01-03	5
2022-01-04	5
.	5
.	5
.	5
2022-07-09	5
2022-07-10	5
2022-07-11	5
2022-07-12	10
2022-07-13	10
2022-07-14	10
.	10
.	10
2022-11-13	10
2022-11-14	10
2022-11-15	3
2022-11-16	3
2022-11-17	3
2022-11-18	3

How can I do that?

Thanks.

Answer 1

Using the window function lead() over() in concert with an ad-hoc tally table

Example

Select Date = dateadd(DAY,N,A.Date)
      ,A.Value
 From  ( 
        Select *
              ,nDays = datediff(DAY,Date,lead(Date,1,dateadd(day,1,'2022-12-01')) over (order by date))
         From  YourTable
       ) A
 Join ( Select Top 1000 N=-1+Row_Number() Over (Order By (Select NULL)) From master..spt_values n1, master..spt_values n2 ) B
   on N<NDays
 Order by Date

Results

Date        Value
2022-01-01  5
2022-01-02  5
2022-01-03  5
2022-01-04  5
2022-01-05  5
...
2022-07-10  5
2022-07-11  5
2022-07-12  10
2022-07-13  10
2022-07-14  10
...
2022-11-12  10
2022-11-13  10
2022-11-14  10
2022-11-15  3
2022-11-16  3
2022-11-17  3
...
2022-11-30  3
2022-12-01  3