SQL: Linking a Count to a specific value through multiple tables - sql

Question

I'm trying to link a COUNT to a specific value across several tables in a SQL Server Database. In this case the tables only share values through correlation. I am returning the values I want but the COUNT is counting everything in a given project not just the ones linked to their work items.
SELECT
[d].[Id]
,COUNT([t].[ItemId]) AS ItemCount
,[d].[ItemName]
FROM
[dbo].[Project_Map] [rm] WITH (NOLOCK)
INNER JOIN
[dbo].[WorkProjects] [r] WITH (NOLOCK)
ON [r].[DomainId] = [rm].[DomainId]
AND [r].[ProjectId] = [rm].[ProjectId]
AND [r].[ReleaseId] = [rm].[ReleaseId]
INNER JOIN
[dbo].[Items] [d] WITH (NOLOCK)
ON [d].[DomainId] = [r].[DomainId]
AND [d].[ProjectId] = [r].[ProjectId]
AND [d].[ReleaseId] = [r].[ReleaseId]
INNER JOIN [dbo].[Projects] [p] with (NOLOCK)
ON r.DomainId = p.DomainId
AND r.ProjectId = p.ProjectId
INNER JOIN [dbo].[Tests] [t] with (NOLOCK)
ON p.DomainId = t.DomainId
AND p.ProjectId = t.ProjectId
INNER JOIN
(
SELECT [Id], MAX([LastModifiedDate]) AS MostRecent
FROM Items
Group By [Id]
) AS updatedItem
ON updatedItem.Id = d.Id
INNER JOIN
[dbo].[WorkItemStates] [ds] WITH (NOLOCK)
ON [ds].[ItemStateName] = [d].[ItemStatus]
WHERE
d.Id = 111111
AND d.UserCategory Like 'SOMESTRING'
GROUP BY d.Id, d.ItemName
RETURNS: In this case the count should be 1 but it returns the count for the entire project.
ID COUNT ITEMNAME
86 5169 SOME NAME
173 5169 SOME NAME
170 5169 SOME NAME
Am I missing a join somewhere?

Answer 1

Currently, your counts are counting all JOIN instances and not just distinct Item level records. Consider turning your Item unit level join into an aggregate query join and include the count field in outer grouping:
Specifically, change:
INNER JOIN [dbo].[Tests] [t] with (NOLOCK)
ON p.DomainId = t.DomainId
AND p.ProjectId = t.ProjectId
Into:
INNER JOIN
(SELECT t.DomaindId, t.ProjectId, Count(*) As ItemCount
FROM [dbo].[Tests] t
GROUP BY t.DomaindId, t.ProjectId) agg
ON p.DomainId = agg.DomainId
AND p.ProjectId = agg.ProjectId
And then the outer query structure becomes:
SELECT
[d].[Id]
,agg.ItemCount
,[d].[ItemName]
FROM
...
GROUP BY
[d].[Id]
,agg.ItemCount
,[d].[ItemName]
Interestingly, you already do such an aggregate query join but never use that derived table updateItem or the field MostRecent.