问题描述

我有一张桌子Person:

PersonID | FirstName | LastName
-------------------------------
1        |   John    |  Doe
2        |   Jane    |  Doe
3        |  NoSpouse | Morales
4        | Jonathan  | Brand
5        | Shiela    | Wife

还有一个 Relationship 表:

RelationshipID | PersonID | Type | RelatedPersonID
1              |    1     |  3   |     2
2              |    2     |  3   |     1
3              |    4     |  3   |     5
4              |    5     |  3   |     4

所以基本上，我想结合配偶和客户的名字，但我想排除配偶:

So basically, I want to combine the names of the spouse and client, but I want to exclude the spouse:

预期结果:

1,  John and Jane Doe, 2
----------------------
3, NoSpouse Morales, null
-----------------------
4, Jonathan and Shiela Brand, 5

我试过了:

SELECT p.PersonID,
    Case when spouse.PersonID is not null 
        THEN p.FirstName + ' and ' + spouse.FirstName + ' ' + p.LastName
    ELSE p.FirstName + ' ' + p.LastName END as ClientName,
    spouse.PersonID as RelatedPersonID
FROM Person p
LEFT JOIN Relationship r on p.PersonID = r.PersonID
LEFT JOIN Person spouse on r.RelatedPersonID = spouse.PersonID
WHERE r.Type = 3 OR spouse.PersonID is null

但结果是:

1,  John and Jane Doe, 2
----------------------
2,  Jane and John Doe, 1
----------------------
3, NoSpouse Morales, null
-----------------------
4, Jonathan and Shiela Brand, 5
-------------------------------
5, Shiela and Jonathan Wife, 4

这是一些模拟数据:

create table Person(
    PersonID int primary key,
    FirstName varchar(max),
    LastName varchar(max)
)
insert into Person values 
(1, 'John', 'Doe'), 
(2, 'Jane', 'Doe'), 
(3, 'NoSpouse', 'Morales'), 
(4, 'Jonathan', 'Brand'), 
(5,'Shiela','Wife')

create table Relationship (
    RelationshipID int,
    PersonID int references Person(PersonID),
    Type int,
    RelatedPersonID int references Person(PersonID)
)
insert into Relationship values 
(1, 1, 3, 2),
(2, 2, 3, 1),
(3, 4, 3, 5),
(4, 5, 3, 4)

SELECT p.PersonID,
    Case when spouse.PersonID is not null 
        THEN p.FirstName + ' and ' + spouse.FirstName + ' ' + p.LastName
    ELSE p.FirstName + ' ' + p.LastName END as ClientName,
    spouse.PersonID as RelatedPersonID
FROM Person p
LEFT JOIN Relationship r on p.PersonID = r.PersonID
LEFT JOIN Person spouse on r.RelatedPersonID = spouse.PersonID
WHERE r.Type = 3 OR spouse.PersonID is null

drop table Relationship
drop table Person

提前感谢您的帮助和时间.

thanks in advance for your help and time.

注意:我已经编辑了我的模拟脚本以在结果中包含 3, NoSpouse Morales, null.此外，对于丈夫/妻子，也不需要特别的标准.列表中最先被提取的人不应包括相关配偶.

NOTE: I've edited my mock script to include 3, NoSpouse Morales, null in the results. Also, there is no particular criteria needed to which is husband/wife. Whoever was fetched first in the list should not include the related spouse.

推荐答案

如果必须包含一个而另一个排除，请尝试添加子句

If one has to be included while the other excluded, try adding a clause

AND r.PersonID < r.RelatedPersonID 

因为 ID 不相等，这将只包括其中一个:

since the IDs will not be equal and this will include only either one:

 SELECT p.PersonID,
 Case when spouse.PersonID is not null 
    THEN p.FirstName + ' and ' + spouse.FirstName + ' ' + p.LastName
 ELSE p.FirstName + ' ' + p.LastName END as ClientName,
 spouse.PersonID as RelatedPersonID
FROM Person p
LEFT JOIN Relationship r on p.PersonID = r.PersonID
LEFT JOIN Person spouse on r.RelatedPersonID = spouse.PersonID
WHERE (r.Type = 3 AND r.PersonID < r.RelatedPersonID)  OR spouse.PersonID is null

这篇关于选择表中的人并排除妻子但合并他们的名字的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！