php - 在 PHP mysqli 中查找 MIN 值但维护行值

Question

我有一个包含 32 行的表，成对的行包含相同的“名称值”，但具有不同的覆盆子值(分别为“一个”和“两个”。)

我想提取具有唯一名称和最低 average_distance 的每一行 - 给我 16 行，为此我正在使用此查询:

SelectFinally();

function SelectFinally (){
    $con = connectToDB();
     $sql = "SELECT name,MIN(average_distance),raspberry From average GROUP BY name";
    $result= mysqli_query($con,$sql);
   $num_rows = mysqli_num_rows($result);

   echo "number of rows"  .$num_rows ."<br />";
        while($row=mysqli_fetch_assoc($result))  {
        extract($row);
        $name = $row['name'];       
       $distance = $row['MIN(average_distance)'];    //."<br />";
       $raspberry = $row['raspberry'];       //."<br />";

echo "select inside selectFinally     name: " .$name  ."    distance:  " .$distance  ."  raspberry    "   .$raspberry ."<br />"; 


    }

此查询为我提供了 average_distance 的最低值，但它弄乱了我的覆盆子值。例如blå_bil 的覆盆子值应为“二”，因此它具有最低的 average_distance - 值。 我似乎做对了。有人可以帮我解决问题吗？

Answer 1

尝试:

SELECT a.name, a.raspberry
FROM   average a
INNER JOIN
(
    SELECT   name, MIN(average_distance) as avg_dist
    FROM     average
    GROUP BY name
) a2 ON a.name = a2.name AND a.average_distance = a2.avg_dist

代替 SELECT name,MIN(average_distance),raspberry From average GROUP BY name