List dates between start and end date in SQL then merge data based on a calendar date

I have a table with purchasing data, for example this below. The purchased items are for the entire year, so there are hundreds of items. I'm looking for a way to list all of the dates of the month, and any date that a purchase was made, it would show for that particular date.I need to generate a SQL Server 2019 report showing daily purchases, including dates with zero purchases.

My current table only includes purchase dates. I need a query to generate a complete calendar of dates and join purchase details to it.

I found this script, but cannot get it to join on the date of purchase. Output should be:

Purchases_Table:

Code:

DECLARE @StartDate date
DECLARE @EndDate date

SELECT DATEADD(day, number, @startdate) Date
FROM master..spt_values 
WHERE type = 'P' 
  AND DATEADD(Day, number, @startdate) <= @enddate

SELECT
    Date, 
    Items, 
    Cost
FROM
    Purchases_Table pt
LEFT JOIN
    dates ON pt.Date

Please assist in figuring out how I can accomplish this.

Hope this helps

DECLARE @StartDate DATE = '2025-01-01';
DECLARE @EndDate DATE = '2025-12-31';

-- Step 1: Create the calendar
WITH Calendar AS (
    SELECT DATEADD(DAY, number, @StartDate) AS Date
    FROM master..spt_values
    WHERE type = 'P'
      AND DATEADD(DAY, number, @StartDate) <= @EndDate
)

-- Step 2: Output with all days, including where there were no purchases
SELECT 
    c.Date,
    ISNULL(p.Items, 0) AS Items,
    ISNULL(p.Cost, 0.0) AS Cost
FROM 
    Calendar c
LEFT JOIN 
    Purchases_Table p ON p.Date = c.Date
ORDER BY 
    c.Date;