从表与一些ID的多行选择，与标识值

Question

目前，我有以下结果：

ID Location 
1  NYC 
1  LA 
2  NYC 
3  PIT 

，我想以下几点：

ID Location 
1  Multiple 
2  NYC 
3  PIT 

有谁知道的简单的方法来完成这一点？

Answer 1

下面是使用case与count和distinct做到这一点的一种方法：

select distinct id, 
    case when count(location) over (partition by id) > 1 
    then 'Multiple' else location end Location 
from yourtable 

• SQL Fiddle Demo

Answer 2

随着sub-query，COUNT，CASE，GROUP BY：

SELECT mm.id, CASE WHEN mm.count > 1 THEN 'Multiple' ELSE loc END As Location 
FROM 
(SELECT COUNT(id) As count, id, MAX(location) As loc 
FROM myTable 
GROUP BY id) As mm; 

SQL Fiddle

Answer 3

select ID,case when MIN(name) = MAX(name) then MIN(name) else 'multiple' end as Location 
from <your tabel name> 
group by id