SQL Query to Count Daily Totals Skips Days - sql

Question

This query counts the amount of bottles we produce over a month and groups them by day. If there are no bottles produces that day then it is skipped from the output instead of returning 0 bottles produced. How can I return with the day's timestamp if there are no bottles produced? I heard the calendar table has to be used for this.
SELECT CONVERT(datetime,CAST(t_stamp AS DATE)), COUNT(bottles) AS 'Good Bottles'
FROM bottles
WHERE t_stamp
BETWEEN "any date"
AND "any date"
GROUP BY CAST(t_stamp AS DATE)
ORDER BY CAST(t_stamp AS DATE) ASC
Current Output:
Aug 12, 2019 12:00 am..................4302
Aug 13, 2019 12:00 am..................2302
Aug 17, 2019 12:00 am..................1302
Aug 18, 2019 12:00 am..................4302
Desired Output:
Aug 12, 2019 12:00 am..................4302
Aug 13, 2019 12:00 am..................2302
Aug 14, 2019 12:00 am..................0
Aug 15, 2019 12:00 am..................0
Aug 16, 2019 12:00 am..................0
Aug 17, 2019 12:00 am..................1302
Aug 18, 2019 12:00 am..................4302

Answer 1

You need to generate the days. A pretty simple method uses a recursive CTE:
WITH dates as (
SELECT CONVERT(date, "any date1") as dte
UNION ALL
SELECT DATEADD(day, 1, dte)
FROM dates
WHERE dte < "any date2"
)
SELECT d.dte, COUNT(bottles) AS GoodBottles
FROM dates d LEFT JOIN
bottles b
ON CAST(t_stamp as DATE) = d.dte
GROUP BY d.dte
ORDER BY d.dte ASC;
Notes:
If you have a calendar or tally table, then use that instead.
If the number of dates exceed 100, you need to add OPTION (MAXRECURSION 0).
COUNT(bottles) looks suspicious. Do you really intend SUM(bottles)?
Converting a column to a date and then to a datetime is also suspicious. It is unclear why you would want a datetime for the first column.