Repeat rows based on range of dates in two columns - mysql

Question

I have a table with following columns:
ID startdate enddate
I want the rows of this table to be repeated as many times as the difference between startdate and enddate along with a column which gives all the dates between these two days for each id in the table. So, my new table should be like this:
ID Date
A startdate
A startdate +1 day
A startdate +2 days (till enddate)
B startdate
B startdate + 1 day ....
Please note that I have different start and end dates for different IDs.
I tried the answer for the following question, but this doesn't work:
Mysql select multiple rows based on one row related date range

Answer 1

Here's one approach.
This uses an inline view (aliased as i to generate integer values from 0 to 999, and that is joined to your table to generate up to 1000 date values, starting from startdate up to enddate for each row.
The inline view i can be easily extended to generate 10,000 or 100,000 rows, following the same pattern.
This assumes that the startdate and enddate columns are datatype DATE. (or DATETIME or TIMESTAMP or a datatype that can be implicitly converted to valid DATE values.
SELECT t.id
, t.startdate + INTERVAL i.i DAY AS `Date`
FROM ( SELECT d3.n*100 + d2.n*10 + d1.n AS i
FROM ( SELECT 0 AS n
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
) d1
CROSS
JOIN ( SELECT 0 AS n
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
) d2
CROSS
JOIN ( SELECT 0 AS n
UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9
) d3
) i
JOIN mytable t
ON i.i <= DATEDIFF(t.enddate,t.startdate)

Answer 2

You need a numbers table... create a temporary table or dummy table that contains the numbers 1 to X (X being the maximum possible difference between the two dates)
Then join to that table using a date diff
I'm afraid I'm SQL Server and so not sure if the datediff functions work the same way in mysql, but you should get the idea.
SELECT
DateTable.Id,
DATEADD(dd, NumbersTable.Number, DateTable.StartDate)
FROM
DateTable
INNER JOIN
NumbersTable
ON
DATEADD(dd, NumbersTable.Number, DateTable.StartDate) <= DateTable.EndDate
ORDER BY
DateTable.Id,
DATEADD(dd, NumbersTable.Number, DateTable.StartDate)

Answer 3

I know its very late to answer
but still one more answer using recursive cte
with recursive cte ( id, startdate) as
(
select id,startdate from test t1
union all
select t2.id,(c.startdate + interval '1 day')::date
from test t2
join cte c on c.id=t2.id and (c.startdate + interval '1 day')::date<=t2.enddate
)
select id,startdate as date from cte
order by id, startdate
its PostgreSQL specific, but it should work in other relational databases with little bit change in Date function.