Question

将表格连接到自身，没有特定的ID

我有一个没有ID列的客户记录表，客户可能会多次出现在表中，并填充了各种列。我已设法构建一个完全弹出但不是客户唯一的INIT_SURNAME列。如何合并行以匹配具有相同INIT_SURNAME并共享另一个公共数据元素的客户。例如，我想从下表返回3个cutomers，前3行是同一个人。

e.g

INPUT：

INIT_SURNAME|EMAIL|PHONE|OTHERID
J*SOAP|js@x.com|4321|
J*SOAP|js@x.com||
J*SOAP||4321|4
J*SOAP|otherjoe@y.com||2
J*DOE||12345|3

输出：

INIT_SURNAME|EMAIL|PHONE|OTHERID
J*SOAP|js@x.com|4321|4
J*SOAP|otherjoe@y.com||2
J*DOE||12345|3

可以这样做吗？

Answer 1

您可以单独合并每列。

T-Sql中的示例代码：

declare @foo table ( 
    name varchar(30), 
    email varchar(30), 
    phone varchar(30), 
    id varchar(30)
)
insert into @foo values 
('J*SOAP','js@x.com','4321',NULL),
('J*SOAP','js@x.com',NULL,NULL),
('J*SOAP',NULL,'4321','4'),
('J*SOAP','otherjoe@y.com',NULL,'2'),
('J*DOE',NULL,'12345','3')

;with 
merge_by_email as (
    select name, email, MAX(phone) as phone, MAX(id) as id 
    from @foo 
    group by name, email
),
merge_by_phone as (
    select name, max(email) as email, phone, MAX(id) as id 
    from merge_by_email 
    group by name, phone
),
merge_by_id as (
    select name, max(email) as email, MAX(phone) as phone, id 
    from merge_by_phone 
    group by name, id
)
select * from merge_by_id

加入一个没有特定ID的表

1 个答案: