Question

我有以下查询...

SELECT DISTINCT
  inv.name,
  loc.city,
  cls.color
FROM INVENTORY inv
INNER JOIN Model mod ON mod.id = inv.id
LEFT OUTER JOIN Location loc ON loc.id = mod.id
LEFT OUTER JOIN Class cls ON cls.id = mod.id
ORDER BY name, city asc;

这将给我以下内容......

   NAME    | CITY      | Color
1  Bob       New York    Red
2  Janet     Denver      Green
3  John      New York    Blue

但我希望的结果是......

   NAME    | CITY      | Color
1  Bob       New York    Red
2  John      New York    Blue

有几个帖子相似但似乎不适用于我的特定查询，因为我使用内部联接和两个左外部联接连接多个表。非常感谢任何帮助！

Answer 1

如果您只想要出现多次的城市，请使用分析函数：

with t as (
      <your query here without the order by>
     )
select t.*
from (select t.*, count(*) over (partition by city) as city_cnt
      from t
     ) t
where city_cnt > 1;

SQL - 仅返回在左外连接的特定列中具有重复值的记录

1 个答案: