SQL query to show users that have null values - sql

Question

I am quite new to SQL and I have a slight issue with my query that I have created, What I have done is created a query that will create a time summary of all of our staffs time recording on a particular day, currently the query works but what I need it to do is bring through a list of all of our users, not just filter by the users that did time recording on that day.
SELECT
SUM(CASE WHEN TimeTransactions.ChargeBasis = 'C' THEN TimeTransactions.QuantityOfTime/60/6 ELSE 0 END) AS ChargableUnits,
SUM(CASE WHEN TimeTransactions.ChargeBasis = 'N' THEN TimeTransactions.QuantityOfTime/60/6 ELSE 0 END) AS NonChargableUnits,
SUM(CASE WHEN TimeTransactions.ChargeBasis = 'C' THEN TimeTransactions.ValueOfTime ELSE 0 END) AS ChargableValue,
SUM(CASE WHEN TimeTransactions.ChargeBasis = 'N' THEN TimeTransactions.ValueOfTime ELSE 0 END) AS NonChargableValue,
SUM(TimeTransactions.QuantityOfTime)/60/6 AS TotalUnits,
SUM(TimeTransactions.ValueOfTime) AS TotalValue,
Users.Code AS FeeEarner
FROM
Users INNER JOIN TimeTransactions ON TimeTransactions.FeeEarnerRef = Users.Code
WHERE
Users.FeeEarner = 1 AND Users.UserStatus = 0 AND
TimeTransactions.TransactionDate >= dateadd(day,datediff(day,1,GETDATE()),0)
AND TimeTransactions.TransactionDate < dateadd(day,datediff(day,0,GETDATE()),0)
GROUP BY
Users.Code
I expect it to show users that did not do time recording on that day as showing 'NULL' in each row instead of removing them from the table.
Any help or guidance will be greatly appreciated :)

Answer 1

Something like this will do it.
Use a CTE to build your user query and place your user related filter conditions in there, then left join this on to your time table and apply your time filter conditions there. This avoids left joining the 2 tables raw but then applying a filter on to the right table which forces an inner join under the hood.
EDIT:
This is a working example of what you are trying to achieve. I have greatly SIMPLIFIED the table structure as the columns referenced in the query supplied don't match the columns provided in the image samples. Also it looks like the query is trying to use a column alias in a where clause (which isn't possible in SQL server).
In the below example I've applied filtering on the timetransaction table in the common table expression and then left joined the user table on to that. This produces the following output.
You can see a zero is returned for users whose time transactions do not match the filtering condition, where using an inner join those users would not be returned at all.
With more comprehensive data examples (that represent the column structure and the expected output or something similar) we could work out a solution which would be far closer to cut and paste ready, whereas this example is simply that, an example of how I would construct a left join where filtering needs to happen in the table on the right hand side of the join.
Good luck, if you have any questions let me know.
declare #users table (
userid int identity(1,1),
username nvarchar(50)
);
declare #timetransaction table (
timetransactionid int identity(1,1),
userid int,
quantityoftime int
);
insert #users
values
('SomeBody'),
('AnyBody'),
('SomeoneElse');
insert #timetransaction
values
(1, 7),
(1, 12),
(2, 5),
(3, 71),
(3, 4);
declare #userid int = 1;
with timetransaction as (select userid, quantityoftime from #timetransaction where userid=1)
select u.userid, coalesce(SUM(quantityoftime), 0) as total from #users u
left join timetransaction t on u.userid=t.userid
group by u.userid;
Example of users table
enter image description here
Example of time transactions table
enter image description here

Answer 2

You should use a LEFT JOIN. But it is very important to get the filtering conditions right:
SELECT SUM(CASE WHEN tt.ChargeBasis = 'C' THEN tt.QuantityOfTime/60/6 ELSE 0 END) AS ChargableUnits,
SUM(CASE WHEN tt.ChargeBasis = 'N' THEN tt.QuantityOfTime/60/6 ELSE 0 END) AS NonChargableUnits,
SUM(CASE WHEN tt.ChargeBasis = 'C' THEN tt.ValueOfTime ELSE 0 END) AS ChargableValue,
SUM(CASE WHEN tt.ChargeBasis = 'N' THEN tt.ValueOfTime ELSE 0 END) AS NonChargableValue,
SUM(tt.QuantityOfTime)/60/6 AS TotalUnits,
SUM(tt.ValueOfTime) AS TotalValue,
u.Code AS FeeEarner
FROM Users u LEFT JOIN
TimeTransactions tt
ON tt.FeeEarnerRef = u.Code AND
tt.TransactionDate >= dateadd(day, -1, CONVERT(date, GETDATE())) AND
tt.TransactionDate < CONVERT(date, GETDATE())
WHERE u.FeeEarner = 1 AND u.UserStatus = 0
GROUP BY u.Code;
Notes:
The conditions on TimeTransactions need to go in the ON clause rather than the WHERE.
SQL Server supports the DATE data type. There is no need to do arcane calculations using date differences to remove the time component from a value.
Table aliases make the query easier to write and to read.