sql - MS SQL中的嵌套连接，不起作用

Question

这是表结构（相关位）：

我正在尝试查找与 clientID 上的声明和声明日期（实际上在 8 小时内）相匹配的 contactLog 条目。这是我想出的：

SELECT
D.ClientID
D.DeclarationID   
CL.ContactDescription,
CL.ContactDate,

FROM Declarations D

INNER JOIN  (Contacts C
         INNER JOIN (PartialContacts PC
             INNER JOIN ContactLogs CL
                ON PC.ContactPartID = CL.ContactPartID )
            on PC.ContactID = C.ContactID
     )  
    ON C.ClientID = D.ClientID AND DATEDIFF(hour, D.DeclarationDate, CL.ContactDate) < 8

但是，连接无法正常运行，因为我得到了 CL.ContactDate 的不匹配日期，很明显它只是返回 CL 中该患者 ID 的每一行。我想...我不太确定出了什么问题。

Answer 1

感谢达米安：

我没有指定 datediff 的下限，所以匹配没有正常工作。显然，连接很好：

SELECT
D.ClientID
D.DeclarationID   
CL.ContactDescription,
CL.ContactDate,

FROM Declarations D

INNER JOIN  (Contacts C
         INNER JOIN (PartialContacts PC
             INNER JOIN ContactLogs CL
                ON PC.ContactPartID = CL.ContactPartID )
            on PC.ContactID = C.ContactID
     )  
    ON C.ClientID = D.ClientID AND DATEDIFF(hour, D.DeclarationDate, CL.ContactDate) < 8 DATEDIFF(hour, D.DeclarationDate, CL.ContactDate) > 0.1

Answer 2

SELECT
D.ClientID
D.DeclarationID   
CL.ContactDescription,
CL.ContactDate
FROM Declarations D
INNER JOIN Clients CL ON D.ClientID=CL.ClientID
INNER JOIN  Contacts CO ON CL.ClientID=CO.ClientID
INNER JOIN PartialContact PC ON PC.ContactID=CO.ContactID
INNER JOIN ContactLog CL ON CL.ContactPartID=PC.ContactPartID
WHERE DATEDIFF(hour, D.DeclarationDate, CL.ContactDate) BETWEEN 0 AND 8