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我在一家拥有案例管理系统的律师事务所工作，该系统将接口链接到 SQL 数据库。我正在 SSRS 中编写查询以运行报告。我正在尝试对案例信息进行报告。一些信息在“cases”表（或 vcases 视图）中是正确的，但我也在尝试从“demands_offers”表中链接信息。每个案例可以有多个需求和报价，因此我在连接中使用 MAX 函数来仅提取每个案例的最新需求记录。不幸的是，这样做消除了没有要求的情况。我需要所有的案例都出现。

我尝试使用嵌套在 MAX 函数中的 CASE 语句将 NULLS 或空字段转换为随机的早期日期，但我仍然无法让所有案例都出现在报告中。

有任何想法吗？我是 SQL 的相对新手，没有受过正规培训。任何帮助将不胜感激。你可以看到下面的代码。（PS 我不认为我有权创建临时表。）

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
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1 回答 1

1

您的查询可能会写得更紧凑，性能更好，但首先，这是在没有要求的情况下删除行的部分：

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

它需要是

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

原因是an(A INNER JOIN B)只在A中的行可以匹配到B中的行时才保留记录。当没有需求时，派生表（子查询）返回NULL max_demands_date，这是无法匹配的do.demands_date = m.max_demands_date。这会导致case记录被删除。

于 2012-12-14T19:17:54.400 回答