Question

I work in a law firm with a case management system which links an interface to a SQL db. I am writing queries in SSRS to run reports. I am trying to run a report on case information. Some of the information is right in the “cases” table (or vcases view), but I’m also trying to link information from a “demands_offers” table. Each case can have multiple demands and offers, so I am using a MAX function in a join to extract only the most recent demand record per case. Unfortunately, doing this eliminates cases which have no demands. I need all the cases to show up.

I have tried using a CASE statement nested in the MAX function to convert NULLS or empty fields to a random early date, but I still can’t get all of the cases to appear in the report.

Any ideas? I am a relative newbie with SQL and have no formal training. Any help would be greatly appreciated. You can see the code below. (P.S. I don’t think that I have the rights to create a temporary table.)

SELECT vc.case_number AS "Matter ID", vc.style, vc.atty2_name AS "Handling Attorney", m.max_demands_date, do.demands, do.demands_notes, sa.authorized,      
(SELECT TOP 1 vl.computename        
FROM vcases vca     
LEFT OUTER JOIN case_parties cp     
ON vca.case_sk = cp.case_sk     
JOIN case_parties cpp       
ON cp.parent_sk = cpp.case_parties_sk       
JOIN vlegal_entity vl       
ON vl.legal_entity_sk = cp.entity_sk        
JOIN vlegal_entity vlp      
ON vlp.legal_entity_sk = cpp.entity_sk      
WHERE (vca.case_sk = vc.case_sk) AND (cpp.role_sk = '3557') AND (cp.role_sk = '3986') ) AS "Plaintiff//'s Attorney",        
(SELECT cp.reference_number     
    FROM cases AS ca    
        LEFT OUTER JOIN case_parties AS cp
        ON ca.case_sk = cp.case_sk
    WHERE (cp.role_sk = '3706')     
        AND (ca.case_sk = vc.case_sk)) AS "Claim Number"


FROM        
vcases vc       
LEFT OUTER JOIN     
case_parties cp ON vc.case_sk = cp.case_sk      
LEFT OUTER JOIN     
vlegal_entity vl ON cp.entity_sk = vl.legal_entity_sk       
LEFT OUTER JOIN     
settle_authority sa ON vc.case_sk = sa.case_sk      
LEFT OUTER JOIN         
demands_offers do ON vc.case_sk = do.case_sk        

INNER JOIN      
 (SELECT DISTINCT max(
(CASE WHEN do.demands_date = '' THEN '1/1/1900 00:00:00'
             ELSE do.demands_date
              END)
  ) as "max_demands_date", vc.case_sk       
   FROM vcases AS vc        
   JOIN demands_offers AS do ON vc.case_sk = do.case_sk     
   GROUP BY vc.case_sk) AS m        
  ON vc.case_sk = m.case_sk  AND        
  do.demands_date = m.max_demands_date      

WHERE (vc.closed_ind = 'O') AND (cp.role_sk = '3816') AND (vl.client_number = 'EAS-01') AND (vc.lawtype_code <> 'FA')       
ORDER BY vc.case_number 

Answer 1

Your query can probably be written to be much more compact and better performing, but to start you off, this is the part that is removing the rows without demands:

INNER JOIN      
 (SELECT DISTINCT max(
(CASE WHEN do.demands_date = '' THEN '1/1/1900 00:00:00'
             ELSE do.demands_date
              END)
  ) as "max_demands_date", vc.case_sk       
   FROM vcases AS vc        
   JOIN demands_offers AS do ON vc.case_sk = do.case_sk     
   GROUP BY vc.case_sk) AS m        
  ON vc.case_sk = m.case_sk  AND        
  do.demands_date = m.max_demands_date 

It needs to be

LEFT JOIN      
 (SELECT DISTINCT max(
(CASE WHEN do.demands_date = '' THEN '1/1/1900 00:00:00'
             ELSE do.demands_date
              END)
  ) as "max_demands_date", vc.case_sk       
   FROM vcases AS vc        
   JOIN demands_offers AS do ON vc.case_sk = do.case_sk     
   GROUP BY vc.case_sk) AS m        
  ON vc.case_sk = m.case_sk  AND        
  do.demands_date = m.max_demands_date 

The reason is that an (A INNER JOIN B) keeps records only when it is possible to match rows in A to rows in B. When there is no demand, the derived table (subquery) returns NULL for max_demands_date, which cannot be matched by do.demands_date = m.max_demands_date. This causes the case record to get removed.