SQL duplicate values of records with multiple joins - sql

Question

My query works fine until I add in the estimate tables, where my data duplicates.
Below is my table structure:
Jobs
| ID | JobNumber |
|----|-----------|
| 1 | J200 |
| 2 | J201 |
Job_Invoices
| ID | InvoiceNumber | JobID |
|----|---------------|-------|
| 10 | I300 | 1 |
| 11 | I301 | 2 |
Invoice_Accounts
| ID | InvoiceId | AccountID | Amount |
|----|-----------|-----------|--------|
| 23 | 10 | 40 | 200 |
| 24 | 10 | 40 | 300 |
| 25 | 10 | 41 | 100 |
| 26 | 11 | 40 | 100 |
Estimates
| ID | JobID |
|----|-------|
| 50 | 1 |
Estimate_Accounts
| ID | EstimateID| AccountID | Amount |
|----|-----------|-----------|--------|
| 23 | 50 | 40 | 100 |
| 24 | 50 | 40 | 100 |
Accounts
| ID | Name |
|----|------|
| 40 | Sales|
| 41 | EXP |
I am trying the below:
SELECT
J.JobNumber,
A.Name AS "Account",
SUM(JA.Amount) AS 'Total Invoiced',
SUM(EA.Amount) AS 'Total Estimated',
FROM
Job J
LEFT JOIN
Job_Invoices JI ON JI.JobID = J.ID
LEFT JOIN
Estimates E ON E.JobID = J.ID
LEFT JOIN
Estimate_Accounts EA ON EA.EstimateID = E.ID
INNER JOIN
Invoice_Accounts JA ON JA.InvoiceId = JI.ID
INNER JOIN
Accounts A ON A.ID = JA.AccountID
GROUP BY
J.JobNumber, A.Name, JA.Amount
ORDER BY
J.JobNumber
This is what I am hoping to achieve:
| JobNumber | Account | Total Invoiced | Total Estimated |
|-----------|-----------|----------------|-----------------|
| J200 | EXP | 100 | 0 |
| J200 | Sales | 500 | 200 |
| J201 | Sales | 100 | 0 |
This works fine if before I add the Estimates and Estimate_Accounts tables, my result looks like the above (without the Total Estimate) column.
However, when I try adding the Total Estimated column by joining the Estimates and Estimate_Accounts tables, Total Invoiced and Total Estimated values double, to something like this:
| JobNumber | Account | Total Invoiced | Total Estimated |
|-----------|-----------|----------------|-----------------|
| J200 | EXP | 200 | 0 |
| J200 | Sales | 1000 | 400 |
| J201 | Sales | 200 | 0 |

Answer 1

You want to join invoice totals with esitimated totals. Both are aggregations. So, make these aggregations, then join. With the jobs and accounts thus found, join the job and account tables.
select
j.jobnumber,
a.name as "Account",
inv.total as "Total Invoiced",
est.total as "Total Estimated",
from
(
select e.jobid, ea.accountid, sum(ea.amount) as total
from estimate_accounts ea
join estimates e on e.id = ea.estimateid
group by e.jobid, ea.accountid
) est
full outer join
(
select ji.jobid, ia.accountid, sum(ia.amount) as total
from invoice_accounts ia
join job_invoices ji on ji.id = ia.invoiceid
group by ji.jobid, ia.accountid
) inv using (jobid, accountid)
join jobs j on j.id = jobid
join accounts a on a.id = accountid
order by j.jobnumber, a.name;
If your DBMS doesn't support the USING clause, you must use ON instead:
select
[...]
) inv on inv.jobid = est.jobid and inv.accountid = est.accountid
join jobs j on j.id in (est.jobid, inv.jobid)
join accounts a on a.id in (est.accountid, inv.accountid)
order by j.jobnumber, a.name;

Answer 2

You need to aggregate before joining, because otherwise the JOIN generates a Cartesian product. However, this is complicated by the account information.
So, this approach aggregates the estimates and invoices separately by account and job. It then combines them using UNION ALL and joins in the rest of the information:
SELECT J.JobNumber, A.Name AS Account,
JE.Total_Invoiced, JE.Total_Estimated
FROM Job J LEFT JOIN
((SELECT JI.JobId, JA.AccountId, SUM(JA.Amount) AS Total_Invoiced, NULL as Total_Estimated
FROM Job_Invoices JI JOIN
Invoice_Accounts JA
ON JA.InvoiceId = JI.ID
GROUP BY JI.JobId, JA.AccountId
) UNION ALL
(SELECT E.JobId, EA.AccountId, NULL, SUM(EA.Amount) as Total_Estimated
FROM Estimates E JOIN
Estimate_Accounts EA
ON EA.EstimateID = E.ID
GROUP BY E.JobId, EA.AccountId
)
) JE
ON JE.JobId = J.ID LEFT JOIN
Accounts A
ON A.ID = JE.AccountID
ORDER BY J.JobNumber;

Answer 3

There are two tables where duplication may happen:
Invoice_Accounts has several records per AccountID/InvoiceId tuple, that you want to SUM()
Estimate_Accounts has several records per EstimateID/AccountID tuple. Also I think that you should use column AccountID when joining this table: this requires changing the order of the JOINs, so Estimate_Accounts is joined after Accounts
I think that it would be simpler to move the aggregation to subqueries, and then join them in the outer query.
Consider:
SELECT
J.JobNumber,
A.Name AS Account,
JA.Amount AS Total_Invoiced,
COALESCE(EA.Amount, 0) AS Total_Estimated
FROM
Job J
LEFT JOIN
Job_Invoices JI ON JI.JobID = J.ID
INNER JOIN
(
SELECT AccountID, InvoiceId, SUM(Amount) Amount
FROM Invoice_Accounts
GROUP BY InvoiceId, AccountID
) JA ON JA.InvoiceId = JI.ID
INNER JOIN
Accounts A ON A.ID = JA.AccountID
LEFT JOIN
Estimates E ON E.JobID = J.ID
LEFT JOIN
(
SELECT EstimateID, AccountID , SUM(Amount) Amount
FROM Estimate_Accounts
GROUP BY EstimateID, AccountID
) EA ON EA.EstimateID = E.ID AND EA.AccountID = JA.AccountID
ORDER BY
J.JobNumber, A.Name;
This demo on DB Fiddle with your sample data returns:
| JobNumber | Account | Total_Invoiced | Total_Estimated |
| --------- | ------- | -------------- | --------------- |
| J200 | EXP | 100 | 0 |
| J200 | Sales | 500 | 200 |
| J201 | Sales | 100 | 0 |