我在表“ customer”中有数据，例如
ID NAME CITY
11 John A
12 Peter B
13 Robin A
14 Steve C
15 Methew D
16 Matt C
17 Nancy C
18 Oliver D
我希望查询仅显示同一城市中每2个客户的数据。
输出应为
ID NAME CITY
11 John A
13 Robin A
15 Methew D
18 Oliver D
以下查询可完成此操作
select a.ID1,a.Name1,a.City,b.cnt_of_customers
from Customers as a,( SELECT City,count(*) as cnt_of_customers
FROM Customers
GROUP BY City
HAVING count(*)=2) as b
where a.city=b.city
尝试
select * from Customer where City IN (
select city from Customer as c
group by city having Count(City) = 2)