Question

我希望在各行之间创建一个指标来查看公司是否销售苹果。例如，给定一个数据帧：

Company |   Product |   Salesperson    
A           Apple       John
A           Banana      John
A           Orange      Jane
B           Orange      John
B           Banana      Sam

我想创建一个dummyvar列来标记所有公司A的1，因为John在那里卖苹果

Company |   Product |   Salesperson    |  IND  
A           Apple       John              1
A           Banana      John              1
A           Orange      Jane              1
B           Orange      John              0

我想在sas或SQL中执行此操作。

Answer 1

在PROC SQL中很容易做到，因为SAS会自动使用摘要统计信息重新合并详细信息行。布尔表达式的计算结果为0/1，因此只需使用MAX（）来确定表达式是否为真。

proc sql ;
create table want as 
  select *,max(product='Apple') as IND
  from have
  group by company
;
quit;

Answer 2

MS SQL Server ：解决方案可能就是这样：

declare @tbl as table (
    company varchar(1)
    ,product varchar(10)
    ,salesPerson varchar(10)
)

insert into @tbl values ('A', 'Apple', 'John')
insert into @tbl values ('A', 'Banana', 'John')
insert into @tbl values ('A', 'Orange', 'Jane')
insert into @tbl values ('B', 'Orange', 'John')
insert into @tbl values ('B', 'Banana', 'Sam')

SELECT
    company
    ,product
    ,salesPerson
    ,CASE WHEN 
        company IN (SELECT company FROM @tbl WHERE product = 'Apple' AND salesPerson = 'John') THEN 1 
        ELSE 0 
    END AS col
FROM @tbl

Answer 3

假设表名为X且IND列已存在，且值为空。

update X
     SET IND = 1
     WHERE Company IN (select distinct(Company) from X where Product = 'Apple' AND Salesperson = 'John')

update X
     SET IND = 0
     WHERE Company NOT IN (select distinct(Company) from X where Product = 'Apple' AND Salesperson = 'John')

跨行创建指标

3 个答案: