Question

输入

+----+----+----+
| in | tn | 20 |
+----+----+----+
| in | ka | 18 |
+----+----+----+
| in | ap | 30 |
+----+----+----+
| us | la | 12 |
+----+----+----+
| us | ca | 20 |
+----+----+----+
| us | ny | 5  |
+----+----+----+

期望输出

+----+----+----+
| in | ka | 18 |
+----+----+----+
| us | ny | 5  |
+----+----+----+

如上面的输出所示，我需要每个国家及其价值最低的州。

select a.country, a.state, a.value
from table1 a
where a.value in (select min(value) from table1);

使用上面的查询，我将根据整个表的最小值获取输出。

+----+----+---+
| us | ny | 5 |
+----+----+---+

我需要每个国家及其各自州的最低价值。

Answer 1

使用您的方法，您需要一个相关的子查询：

select a.country, a.state, a.value
from table1 a
where a.value in (select min(value)
                  from table1 b
                  where a.country = b.country);

Answer 2

您也可以尝试 -

SELECT b.* 
FROM mytable b 
JOIN (SELECT country,MIN(val) AS val FROM mytable GROUP BY country) AS a ON b.val=a.val AND a.country=b.country

Answer 3

select country,min(value) from table1 group by country

Answer 4

许多方法可以做到这一点，例如：

SELECT a.country,
  ( SELECT b.state
    FROM table1 b
    WHERE b.country = a.country AND b.value = MIN(a.value)) state,
  MIN(a.value)
FROM table1 a
GROUP BY a.country

Answer 5

尝试以下，

您可以对此查询使用排名功能。

Select country, state, value from  
(
    Select row_number() over (order by country, value) as row_id ,
    country, state, value
)T
where row_id == 1

Answer 6

无需子查询或加入！很简单：

+----+----+----+
| in | ka | 18 |
+----+----+----+
| us | ny | 5  |
+----+----+----+

输出：

{{1}}

SQL Query用于获取多个最小值

6 个答案: