SQL GROUP BY，HAVING和排序（MySQL的）

Question

我有以下SQL：

select code, distance from places;  

的輸出如下：

CODE  DISTANCE 
106  386.895834130068 
80  2116.6747774121 
80  2117.61925131453 
106  2563.46708627407 

我希望能夠只得到一個單碼和最近的距離。所以我想讓它迴歸：

CODE  DISTANCE 
106  386.895834130068 
80  2116.6747774121 

仍在玩Distinct和Group By。

Answer 1

select `code`, min(distance) as minimal_distance 
from places 
group by `code` 

Answer 2

select code, min(distance) as mindist 
from places 
group by code 

Answer 3

select code, min(distance) as distance 
from places 
group by code 

在這裏，你已經手冊GROUP BY： http://dev.mysql.com/doc/refman/5.0/en/group-by-functions-and-modifiers.html

教程：

• http://www.tizag.com/mysqlTutorial/mysqlgroupby.php/
• http://www.w3schools.com/sql/sql_groupby.asp

Answer 4

試試這個：

SELECT 
    Code, 
    MIN(Distance) AS closest_distance 
FROM 
    your_table 
GROUP BY 
    Code 

Answer 5

select `code`, min(distance) as distance 
from places 
group by `code`