New to SQL how do I get both contactsid's from contacts and tasks using a left outter join?

Question

I wrote this report to display how long it takes a user to finish their first task. currently it will only display contacts that have tasks. I need it to display both contacts with and without tasks any ideas?

SELECT c.MarketSource                                                                                   AS [Market Source],
       Coalesce(u.FirstName + ' ', ' ') + Coalesce(u.LastName, ' ')                                     AS [Producer],
       Coalesce(c.FirstName + ' ', ' ') + Coalesce(c.MiddleName + ' ', ' ') + Coalesce(c.LastName, ' ') AS [Lead Name],
       t.TaskType                                                                                       AS [Task],
       Coalesce (t.workflow_resultchosen_label, t.result, ' ')                                          AS [Task Result],
       Dateadd(HOUR, @utcoffset, c.createdon)                                                           AS [Received On],
       Dateadd(HOUR, @utcoffset, ( MIN (t.completed) ))                                                 AS [Completed],
       (SELECT COUNT(*)
        FROM   Quotes q WITH (NOLOCK)
        WHERE  SaleID IS NULL
               AND c.ContactID = q.ContactID)                                                           AS [Pending Quotes],
       (SELECT COUNT(*)
        FROM   Sales s WITH (NOLOCK)
        WHERE  s.Client_ID = c.ContactID)                                                               AS [Total Sales]
FROM   Tasks t WITH (NOLOCK)
       LEFT JOIN Users U WITH (NOLOCK)
         ON u.UserID = t.UserID
       LEFT JOIN Contacts C WITH (NOLOCK)
         ON c.ContactID = t.TargetID
WHERE  iLeadPartnerID IS NOT NULL
       AND ( c.CreatedOn BETWEEN @startDate AND @endDate )
       AND MarketSource IS NOT NULL
       AND c.WorkgroupId = @workgroupID
       AND Len(c.MarketSource) > 0
       AND t.TaskType <> '[=] Auto Email'
GROUP  BY c.MarketSource,
          u.LastName,
          u.FirstName,
          c.ContactId,
          c.LastName,
          c.FirstName,
          c.MiddleName,
          c.CreatedOn,
          t.TaskType,
          t.Result,
          t.Workflow_ResultChosen_Label
ORDER  BY c.LastName,
          c.MiddleName,
          c.FirstName 

Answer 1

You need to use a Left Join from Contacts to Tasks (i.e., show all contacts and any matching Tasks). In addition, you need to move the criteria t.TaskType <> '[=] Auto Email' to the ON clause or change the Where clause filter to be:

(t.TaskType <> '[=] Auto Email' Or t.TaskType Is Null).

Otherwise, your Left Join to Tasks will effectively become an Inner Join.

SELECT c.MarketSource AS [Market Source]
    , Coalesce(u.FirstName + ' ', ' ') + Coalesce(u.LastName, ' ') AS [Producer]
    , Coalesce(c.FirstName + ' ', ' ') + Coalesce(c.MiddleName + ' ', ' ') + Coalesce(c.LastName, ' ') AS [Lead Name]
    , t.TaskType AS [Task], Coalesce (t.workflow_resultchosen_label, t.result, ' ') AS [Task Result]
    , Dateadd(HOUR, @utcoffset, c.createdon) AS [Received On]
    , Dateadd(HOUR, @utcoffset, ( MIN (t.completed) )) AS [Completed]
    , (SELECT COUNT() FROM Quotes q WITH (NOLOCK) WHERE SaleID IS NULL AND c.ContactID = q.ContactID) AS [Pending Quotes]
    , (SELECT COUNT() FROM Sales s WITH (NOLOCK) WHERE s.Client_ID = c.ContactID) AS [Total Sales] 
From Contacts As C WITH (NOLOCK)
    Left Join Tasks t WITH (NOLOCK) 
        On t.TargetID = C.ContactId
            And t.TaskType <> '[=] Auto Email' 
    LEFT JOIN Users U WITH (NOLOCK) 
        ON u.UserID = t.UserID 
WHERE iLeadPartnerID IS NOT NULL 
    AND ( c.CreatedOn BETWEEN @startDate AND @endDate ) 
    AND MarketSource IS NOT NULL 
    AND c.WorkgroupId = @workgroupID 
    AND Len(c.MarketSource) > 0 
GROUP BY c.MarketSource, u.LastName, u.FirstName, c.ContactId
    , c.LastName, c.FirstName, c.MiddleName, c.CreatedOn, t.TaskType
    , t.Result, t.Workflow_ResultChosen_Label 
ORDER BY c.LastName, c.MiddleName, c.FirstName