1

为什么这个查询不起作用？

$query = ("SELECT * FROM 
                (SELECT *, (
                (((endingLatitude - " . $h . ")(endingLatitude - " . $h . "))
                /" . pow($r1, 2) . ")
                 + 
                 ((endingLongitude - " . $k . ")(endingLongitude - " . $k . "))
                 /" . pow($r2, 2) . "
                 ) AS point2 
                FROM (SELECT *, ((
                (
                ((startingLatitude - " . $h . ")(startingLatitude - " . $h . "))
                /" . pow($r1, 2) . ") 
                + 
                ((startingLongitude - " . $k . ")(startingLongitude - " . $k . "))
                /" . pow($r2, 2) . ")) 
                AS point1 
                FROM (SELECT * FROM trips WHERE distance >='" . ($distance * .25) . "') as query1)
                 as query2) as query3 WHERE point1 <= 1 AND point2 <= 1 LIMIT 0 , 10;");

$result = mysqli_query($con, $query);

$h 和 $k 分别是椭圆的 x 和 y 坐标。我正在使用此处找到的公式来计算两个点 (startingLat,startingLong) 和 (endingLat,endingLong) 是否在垂直高度为 $r1 和水平高度为 $r2 的椭圆内。我还将搜索的行限制为距离单元格值大于 $distance * .25 的行。

我认为这可能与括号错误有关，或者与我子查询/执行计算的方式有关。

使用

die(mysqli_error($con));

返回错误You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(endingLatitude - 36.9564753)) /796.842964388) + ((endingLongitud' at line 3

4

1 回答 1

2

我相信你必须使用Mysql乘法算术运算符，*。 https://dev.mysql.com/doc/refman/5.0/en/arithmetic-functions.html#operator_times

代替：

(endingLatitude - " . $h . ")(endingLatitude - " . $h . ")

做这个...

(endingLatitude - " . $h . ") * (endingLatitude - " . $h . ")
于 2015-05-29T05:01:51.243 回答