php - 将2列中的精确串联值分组？

我有一个具有两列纬度和经度的表，希望对两列上的完全匹配（只是）串联值进行分组。
表行：

/* Points Table */
time    |lat    |long
113     |2.1    |5.8
114     |2.1    |5.6    -Set as Group
115     |2.1    |5.6    -Set as Group
116     |2.1    |5.6    -Set as Group
117     |2.1    |5.6    -Set as Group
118     |2.3    |5.2
119     |2.4    |5.3
120     |2.5    |5.3    -Set as Group
121     |2.5    |5.3    -Set as Group
122     |2.6    |5.3
123     |2.1    |5.6    -Set as Group
201     |2.1    |5.6    -Set as Group
202     |2.1    |5.6    -Set as Group
203     |2.5    |5.3

结果必须是：

/* Points Table */
time    |lat    |long
113     |2.1    |5.8
114     |2.1    |5.6    -Grouped as 1 with first tandem time
118     |2.3    |5.2
119     |2.4    |5.3
120     |2.5    |5.3    -Grouped as 1 with first tandem time
122     |2.6    |5.3
123     |2.1    |5.6    -Grouped as 1 with first tandem time
203     |2.5    |5.3

我只想分组串联的值，在上面我们有两个时间串联的2.1 & 5.6值和组是分开的。（用于测试可以在http://sqlfiddle.com/#!2/5d196上工作）。;)

最佳答案

您可以使用PHP完成此操作：

$query = mysqli_query("SELECT time, lat, `long` FROM Points ORDER BY time");

// output header row
echo str_pad('time', 8) .'|';
echo str_pad('lat', 7) .'|';
echo "long\n";

$prevLat = $prevLong = '';
while ($row = mysqli_fetch_assoc($query)) {
    if ($row['lat'] === $prevLat && $row['long'] === $prevLong) {
        // if this row's lat and long values are the same as the
        // previous row's values, skip this row.
        continue;
    }

    $prevLat  = $row['lat'];
    $prevLong = $row['long'];

    echo str_pad($row['time'], 8) .'|';
    echo str_pad($row['lat'], 7) .'|';
    echo "{$row['long']}\n";
}

这里有一个示例：http://codepad.org/c0SjA058

关于php - 将2列中的精确串联值分组？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/13252936/