SQL Statement that Subs 0 for no Results - sql

Question

I am having an issue getting the results I want from my SQL statement. I know I'm probably missing something simple but I just can't see it.
Here are my tables.
Table: Users (RoleID is linked to ID in Roles Table)
ID, FirstName, LastName, RoleID
1, Matt, Ryan, 1
2, Chipper, Jones, 1
3, Julio, Jones, 2
4, Jason, Bourn, 3
Table: Roles
ID, Name
1, Field Rep
2, Tech
3, Admin
Table: FRrequests (UserID is linked to ID in Users table)
ID, UserID, Status
1, 1, Open
2, 1, Submitted
3, 1, Delayed
4, 1, Complete
What I want is an SQL statement that shows me a count of all the "Submitted" & "Delayed" requests for all the Field Reps. Below is an example of desired results.
Name Count
Chipper Jones 0
Matt Ryan 2
Here is the statement I have so far and the results it gives me.
SELECT Users.FirstName + ' ' + Users.LastName AS Name, COUNT(FRrequests.ID) AS 'Open Requests'
FROM Users INNER JOIN
Roles ON Users.RoleID = Roles.ID LEFT OUTER JOIN
FRrequests ON Users.ID = FRrequests.UserID
WHERE (Roles.Name = N'Field Rep') AND (FRrequests.Status = 'Submitted' OR FRrequests.Status = 'Delayed')
GROUP BY Users.FirstName, Users.LastName
Name Count
Matt Ryan 2
I know that the "AND (FRrequests.Status = 'Submitted' OR FRrequests.Status = 'Delayed')" part is what is breaking it. If I run it without that in the statement I get all the users but it counts all status not just submitted and delayed. I just can't figure out what I'm missing to get this to work. Any help would be greatly appreciated.

Answer 1

You are really close, try the following:
SELECT U.FirstName + ' ' + U.LastName AS Name, COUNT(F.ID) AS 'Open Requests'
FROM Users U
INNER JOIN Roles R
ON U.RoleID = R.ID
LEFT JOIN ( SELECT * FROM FRrequests
WHERE Status IN ('Submitted','Delayed')) F
ON U.ID = F.UserID
WHERE R.Name = N'Field Rep'
GROUP BY U.FirstName, U.LastName

Answer 2

You need to have a row for each Field Rep if you wish to include Field Reps that have no requests. Therefore you need to use a left outer join along the following lines:
SELECT
u.FirstName || ' ' || u.LastName as Name
, COALESCE(frr.Counter,0) as Count
FROM
Users u
LEFT OUTER JOIN (
SELECT
UserID
,count(*) as Counter
FROM
FRrequests
WHERE
Status IN ('Submitted', 'Delayed')
GROUP BY
UserID
) frr ON frr.UserID = u.ID
, Roles r
WHERE
u.ID = f.UserID
AND u.RoleID = r.ID
AND r.Name = 'Field Rep'
;
A left outer join will provide a join only where a match occurs, so it does not remove rows from the naturally joined set. In this case you will get a list of all Users who are Field Reps, together with a count of their FRrequests with a 'Submitted' or 'Delayed' status if any.
COALESCE is used (in Postgresql at least) to check for a null value and then coerce it to the supplied value, in this case 0. So if a NULL value occurs (because, for instance, there was no 'Counter' value returned from the left outer join) it is replaced by 0.