sql - 在六边形区域中选择相邻单元格

Question

想象一下具有 3 个维度的六边形空间。

每个图 block 都有坐标 XYZ。我需要在同一平面上选择给定的小区邻居。使用 SQL 它看起来像:

$tbDir = $y % 2 == 0 ? -1 : 1;

$result =  db_query('SELECT x,y,z FROM {cells} WHERE
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d OR
                    x = %d AND y = %d AND z = %d ',
                    $x, $y, $z,
                    $x-1, $y, $z,
                    $x+1, $y, $z,
                    $x, $y-1, $z,
                    $x, $y+1, $z,
                    $x+$tbDir, $y-1, $z,
                    $x+$tbDir, $y+1, $z);

但是，我不喜欢这样。也许有人知道更优化的算法？谢谢!

Answer 1

这看起来你可以使用 between

x BETWEEN $x-1 AND $x+1 AND y BETWEEN $y-1 AND $y+1 AND z = $z

这可能不适用于 $tbDir 部分。我将更详细地查看此案例。

好的，不如试试这个

WHERE   x BETWEEN ($x-1 AND $x+1 AND y = $y AND z = $z)
OR      (y BETWEEN $y-1 AND $y+1 AND x = $x AND z = $z)
OR      (y BETWEEN $y-1 AND $y+1 AND x = $x + $tbDir AND z = $z)

甚至

WHERE   (   (x BETWEEN $x-1 AND $x+1 AND y = $y )
            OR      (y BETWEEN $y-1 AND $y+1 AND x = $x)
            OR      (y BETWEEN $y-1 AND $y+1 AND x = $x + $tbDir)
        )
AND     z = $z