Iterate through SQL table creating another SQL Table - sql

Question

Wonder if someone could cast an eye over the following problem:
I'm running a SQL SELECT statement which gives me the following results:
DATE NumberOfHours
2017-05-01 4
2017-06-01 38
2017-07-01 68
And what I'm trying (like to be able to) to do is off the back of this table create another table that contains 4 rows for 2017-05-01, 38 Rows for 2017-06-01 and 68 rows for 2017-07-01. So I end up with a table that's got 110 rows in it.
I'm at a bit of a loss as to how this could be achieved...could anyone assist?
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Using the response listed by Gordon Linoff I managed to get this working working by using:
with cte as (
SELECT DATEADD(month, datediff(month,0,L.DateAdded),0) AS 'Date', CEILING(SUM(l.CPDHours))AS NumberOfHours
FROM WebsiteICA_SF.dbo.CPD_Log L
WHERE L.DateAdded >= DATEADD(month, -6, GETDATE())
AND (L.Provider = 'ICA' OR L.Provider like 'International Compli%')
GROUP BY DATEADD(month, datediff(month,0,L.DateAdded),0)
union all
select date, NumberOfHours - 1
from cte
where NumberOfHours > 1
)
select 1 AS 'ObId', date, 'ICA' AS Provider, '# ICA' AS DataType
from cte
order by DATEADD(month, datediff(month,0,cte.Date),0)
OPTION (maxrecursion 10000);

Answer 1

One simple method is a recursive CTE:
with cte as (
select date, NumberOfHours
from t
union all
select date, NumberOfHours - 1
from cte
where NumberOfHours > 1
)
select date
from cte;
By default, this is limited to a maximum of 100 hours. However, that is easily changed using the MAXRECURSION option.
Other methods generally rely on a second table to generate numbers. I also like this approach because it is a gentle introduction to recursive CTEs.
Here is a nice SQL Fiddle.

Answer 2

So you have a result set with 3 rows and one column in it which tells you how many rows it represents. You want to generate that many rows.
Not sure what you want to store in that, but here is a solution to the base problem:
Create a table (temp table or CTE is fine too) which contains only one column, storing numbers from 0 to whatever. This is called Tally Table or Numbers Table.
Join this table to your resultset:
WITH NumbersCTE AS (
-- This will give you a bunch of Numbers
-- Persist a table if you want to use it more frequently
SELECT ROW_NUMBER() OVER (ORDER BY name) AS Number FROM sys.columns
)
SELECT
MT.Date,
N.Number
FROM
dbo.MyTable MT
INNER JOIN NumbersCTE N
ON N.Number <= MT.NumberOfHours
As Pieter Geerkens pointed out in the comments, the above method is not the best to generate a numbers table, but for demostration puposes it is fine.
For more info about how to generat tally tables in SQL Server, you can check
http://www.sqlservercentral.com/blogs/dwainsql/2014/03/27/tally-tables-in-t-sql/