Question

我创建了一个简单的Access数据库，其中包含表结构和查询的示例。两个表，人员（包含3个记录）和地址（包含5个记录），提供了为每个人捕获多个地址的功能。我对正常的条件语句很满意，但是这让我陷入了循环... 我正在寻找一个查询，该查询将仅返回给定人员的最新地址。 Table Relationship

查询的当前SQL：

SELECT Person.PersonID_PK, Address.Address, Address.StatusDate
FROM Person INNER JOIN Address ON Person.[PersonID_PK] = Address.PersonID_FK;

我目前的回报：

EmployeeID_PK  Address                         StatusDate
1               12 Elm St, MN  23569            11/13/2017
1               15 Apple Ln, NY 12345           7/15/2018
2               30 Mulberry, TN 38456           6/11/2018
2               10 Lonesome Pine, KY 15487      12/4/2018
3               100 Plaze Place, LA 14563       6/17/2018

我需要返回每个人以及最大（最新）的StatusDate 我的预期回报应该是：

EmployeeID_PK  Address                             StatusDate
1               15 Apple Ln, NY 12345                7/15/2018
2               10 Lonesome Pine, KY 15487           12/4/2018
3               100 Plaze Place, LA 14563            6/17/2018

Answer 1

您可以使用相关子查询：

User updatedUser = new User();
updatedUser.OnPremisesExtensionAttributes = new OnPremisesExtensionAttributes();
updatedUser.OnPremisesExtensionAttributes.ExtensionAttribute8 = "1";

Answer 2

使用具有排名功能的CTE可以很好地工作。

;WITH empaddress AS 
( 
           SELECT     person.personid_pk, 
                      address.address, 
                      address.statusdate, 
                      Dense_rank() OVER (partition BY id ORDER BY statusdate DESC) AS d_rank 
           FROM       person 
           INNER JOIN address 
           ON         person.[PersonID_PK] = address.personid_fk; ) 
SELECT person.personid_pk, 
       address.address, 
       address.statusdate 
FROM   empaddress 
WHERE  d_rank = 1;

Answer 3

感谢您的帮助。我修改了戈登的代码以支持我的查询，以下提供了答案。

SELECT Person.PersonID_PK, Address.Address, Address.StatusDate
FROM Person 
INNER JOIN Address 
ON Person.[PersonID_PK] = Address.PersonID_FK
WHERE (((Address.StatusDate)=(SELECT MAX(Address.StatusDate)
FROM Address
WHERE Person.PersonID_PK = Address.PersonID_FK)));

如何获得每个人的最新地址

3 个答案: