SQL Select Sequential Dates with Additional Lookup Values - sql-server

Question

I am trying to grab a series of dates and the corresponding values (if any) that exist in my database.
I have two parameters - today (date using getDate()) - and a number of days (integer). For this example, I'm using the value 10 for the days.
Code to get the sequential dates for 10 days after today:
SELECT top 10 DATEADD(DAY, ROW_NUMBER()
OVER (ORDER BY object_id), REPLACE(getDate(),'-','')) as Alldays
FROM sys.all_objects
I now need to look up several values for each day in the sequential days code, which may or may not exist in the time table (we assume 8 hours for all dates, unless otherwise specified). The lookup would be on the field recordDateTime. If no "hours" value exists in the table cap_time for that date, I need to return a default value of 8 as the number of hours. Here's the base query:
SELECT u.FullName as UserName, d2.department,
recordDateTime, ISNULL(hours,8) as hours
FROM cap_time c
left join user u on c.userID = u.userid
left join dept d2 on u.deptID = d2.DeptID
WHERE c.userid = 38 AND u.deptID = 1
My end result for the next 10 days should be something like:
Date (sequential), Department, UserName, Number of Hours
I can accomplish this using TSQL and a temp table, but I'd like to see if this can be done in a single statement. Any help is appreciated.

Answer 1

Without any DDL or sample data it's hard to determine exactly what you need.
I think this will get you pretty close (note my comments):
-- sample data
------------------------------------------------------------------------------------------
DECLARE #table TABLE
(
fullName varchar(10),
department varchar(10),
[hours] tinyint,
somedate date
);
INSERT #table VALUES
('bob', 'sales', 5, getdate()+1),
('Sue', 'marketing', 3, getdate()+2),
('Sue', 'sales', 12, getdate()+4),
('Craig', 'sales', 4, getdate()+8),
('Joe', 'sales', 18, getdate()+9),
('Fred', 'sales', 10, getdate()+10);
--SELECT * FROM #table
;
-- solution
------------------------------------------------------------------------------------------
WITH alldays([day]) AS -- logic to get your dates for a LEFT date table
(
SELECT TOP (10)
CAST(DATEADD
(
DAY,
ROW_NUMBER() OVER (ORDER BY object_id),
getdate()
) AS date)
FROM sys.all_objects
)
SELECT d.[day], t.fullName, department, [hours] = ISNULL([hours], 8)
FROM alldays d
LEFT JOIN #table t ON d.[day] = t.somedate;
Results:
day fullName department hours
---------- ---------- ---------- -----
2017-04-12 bob sales 5
2017-04-13 Sue marketing 3
2017-04-14 NULL NULL 8
2017-04-15 Sue sales 12
2017-04-16 NULL NULL 8
2017-04-17 NULL NULL 8
2017-04-18 NULL NULL 8
2017-04-19 Craig sales 4
2017-04-20 Joe sales 18
2017-04-21 Fred sales 10

Answer 2

Maybe a subquery and the in statement, like:
SELECT u.FullName as UserName, d2.department,
recordDateTime, ISNULL(hours,8) as hours
FROM cap_time c
left join user u on c.userID = u.userid
left join dept d2 on u.deptID = d2.DeptID
WHERE c.userid = 38 AND u.deptID = 1 and recordDateTime in
(SELECT top 10 DATEADD(DAY, ROW_NUMBER()
OVER (ORDER BY object_id), REPLACE(getDate(),'-','')) as Alldays
FROM sys.all_objects)