SQL Statement Issue combining 4 tables to get the correct information to display - sql

Question

I am having trouble figuring this one out. I'm using MS SQL 2008 and trying to add the total tech hours from the unbilled table and the billed tables and group them together. I also need to exclude rows for the billed hours based on the report header on a third table if the billed report is voided. I then need to grab the tech names from a 4th table. The unbilled table is SCQReportLabors which lists all the labor records. SCReportLabors table lists all the billed labor records. SCReports is the billed report header which I need to figure out if the VoidID column is null. ShAgents table holds the tech names. Below is what I currently have and I know it doesn't work but it's what I've got so far. For my output data I woul like a TotalHours column and a TechName column. If I end up with a billed total, unbilled total and techname column I can live with that as well. I've been staring at this for a little while and need some perspective and advice. Thanks in advance for any help.
SELECT a.TotalHours, c.PrefFullName AS TechName
FROM (SELECT SUM(LaborHours)+SUM(OvertimeHours)+SUM(TravelHours) AS TotalHours, TechnicianID
FROM SCReportLabors
LEFT OUTER JOIN SCReports d ON a.ReportID = d.ReportID
WHERE d.VoidID IS NULL
GROUP BY TechnicianID) a
JOIN (SELECT SUM(LaborHours)+SUM(OvertimeHours)+SUM(TravelHours) AS TotalHours, TechnicianID
FROM SCQReportLabors
GROUP BY TechnicianID) b
ON a.TechnicianID = b.TechnicianID
LEFT OUTER JOIN ShAgents c ON a.TechnicianID = c.AgentID
ORDER BY c.PrefFullName

Answer 1

This query should capture all data and handles null hours.
SELECT
A.PrefFullName AS 'TechName',
(ISNULL(B.TotalHours, 0) + ISNULL(C.TotalHours, 0)) AS 'Total Hours'
FROM
ShAgents AS A
LEFT OUTER JOIN
(
SELECT
(
SUM(ISNULL(LaborHours, 0)) +
SUM(ISNULL(OvertimeHours, 0)) +
SUM(ISNULL(TravelHours, 0))
) AS 'TotalHours',
TechnicianID
FROM
SCReportLabors AS tA
LEFT OUTER JOIN SCReports AS tB
ON tA.ReportID = tB.ReportID
WHERE
tB.VoidID IS NULL
GROUP BY
TechnicianID
) AS B
ON A.AgentID = B.TechnicianID
LEFT OUTER JOIN
(
SELECT
(
SUM(ISNULL(LaborHours, 0)) +
SUM(ISNULL(OvertimeHours, 0)) +
SUM(ISNULL(TravelHours, 0))
) AS 'TotalHours',
TechnicianID
FROM
SCQReportLabors
GROUP BY
TechnicianID
) AS C
ON A.AgentID = C.TechnicianID
ORDER BY
A.PrefFullName

Answer 2

I made the two main queries a UNION query and also touched up on JOIN for the VOID column.
SELECT SQ1.TotalHours, SHA.PrefFullName AS TechName
FROM
(
SELECT SUM(TOTALHOURS) AS TotalHours, TechnicianID
(SELECT SUM(LaborHours)+SUM(OvertimeHours)+SUM(TravelHours) AS TotalHours, TechnicianID
FROM SCReportLabors L
JOIN SCReports RPTS
ON L.ReportID = RPTS.ReportID
WHERE RPTS.VoidID IS NULL
GROUP BY TechnicianID)
UNION ALL
(SELECT SUM(LaborHours)+SUM(OvertimeHours)+SUM(TravelHours) AS TotalHours, TechnicianID
FROM SCQReportLabors
GROUP BY TechnicianID
)
) SQ
GROUP BY TechnicianID
JOIN ShAgents SHA
ON SQ.TechnicianID = SHA.AgentID
ORDER BY SHA.PrefFullName