IF EXISTS (SELECT 1 FROM SYSOBJECTS WHERE name = 'tba')
BEGIN
    DROP TABLE tba
END
GO
create table tba
([关键词] varchar(6),[分类] varchar(4),[数量] int)

insert tba
select '已付款','买家',3 union all
select '已付款','支付',4 union all
select '发货','卖家',5




select    B.[关键词],
        stuff(( select '/'+ [分类] 
                from tba AS A
                where A.关键词 = B.关键词 for xml path('')),1,1,'') as [分类],
        MAX([数量]) AS [数量]
from tba AS B
GROUP BY B.[关键词]

关键词    分类    数量
发货    卖家    5
已付款    买家/支付    4