Question

我有一个这样的结果表（在运行查询之后）：

     id     |  time  | region
12x-4nm-334 | 16:00  | Utah
12x-4nm-334 | 17:00  | California
12x-4nm-334 | 19:00  | Missouri
12x-4nm-334 | 22:00  | California
983-n2n-aq2 |  8:00  | New York
983-n2n-aq2 |  9:00  | New York

此表中还有一些其他列，但重要的是我要删除仅从结果中注册到一个区域的ID。所以像＆＃34; 983-n2n-aq2＆＃34;只显示在单个区域（不论时间）不应出现在结果表中。

希望这个问题足够清楚。

Answer 1

如果您使用MySql

    DELETE FROM table 
    WHERE id IN (   SELECT x.id
                    FROM (  select *
                            FROM table t
                            GROUP BY id
                            HAVING COUNT(DISTINCT region) = 1
                           ) as x
                    )

我不知道Vertica。希望有所帮助

Answer 2

试试这个：

SELECT id, count(DISTINCT region) as RegionCount
FROM table
GROUP BY
    id
HAVING count(DISTINCT region) > 1

如果您的DBMS不支持count(distinct )，那么应该这样做：

SELECT id, count(DISTINCT region) as RegionCount
FROM (
    SELECT id, region FROM table GROUP BY id, region
) as table
GROUP BY
    id
HAVING count(DISTINCT region) > 1

Answer 3

试试这个（借用Geerkens先生）：

SELECT a.*
FROM table a INNER JOIN
(
    SELECT id
    FROM table
    GROUP BY id
    HAVING count(DISTINCT region) > 1
) b ON a.id = b.id

Answer 4

首先获取具有多个不同区域的ID（如子查询中所示），然后在WHERE子句中使用它进行过滤。

SELECT id, time, region
FROM mytable
WHERE id IN
(
    SELECT id
    FROM mytable
    GROUP BY id
    HAVING count(DISTINCT region) > 1
)

SQL删除某些重复的值

4 个答案: