表结构如下
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Buyer Name Quantity
A 甲 2
B 乙 4
C 丙 1
A 丁 2
B 丙 5

请给出所有购入商品为两种或两种以上的购物人记录
select Buyer as 顾客,count(name) as 商品种类数 from table group by Buyer having count(name)>=2
select * from table where Buyer in (select Buyer from table group by Buyer having count(name)>=2)