Question

我需要使用PHP将从URL中获取的字符串与MySQL数据库中的城市列表进行比较

SELECT 'city' WHERE 'city' IN (" . $citynameArray . ") LIMIT 1;

$citynameArray是$cityname所有可能排列的列表，其中$cityname最多可包含5个以连字符分隔的字符串，但'city'可以使用空格或连字符将每个字符串分开。

所以'城市'可能看起来像这些：

字符串
字符串字符串
字符串字符串
字符串字符串字符串
字符串字符串字符串字符串
字符串字符串
字符串字符串字符串
字符串字符串字符串字符串
字符串字符串字符串字符串字符串
string string-string
string-string string
string-string string string
string string-string-string
string string string-string
string string string-string
string-string-string string
string-string string-string
string-string-string string
string-string string string string
string-string-string string string
string-string-string-string string

......依此类推，最多可分为5个字符串

然而，在绝大多数情况下，“城市”要么是：

字符串
字符串字符串
字符串字符串

或者，不太常见：

string-string string
string string-string

我的问题是，如何生成数组？并且，通过使用'LIMIT 1'，一旦找到结果，查询是否会停止循环遍历数组？

我很欣赏任何见解，

的问候，

GJ

Answer 1

我曾希望优雅，但这必须要做。

CASE 1代表90％的用例，开销可以忽略不计。

用例百分比折旧为案例5，适用于2000个案例中的1个案例。我分析了CASE 4的实际模式，模式并不一定是详尽无遗的。

    // FIRST, CREATE AN ARRAY OF $LocaleURL PATTERNS, TAKING INTO ACCOUNT THE VARIABLE USE OF HYPHENS

    $urlCityArray=explode("-",$LocaleURL);
    $countSegs = (count($urlCityArray)); // how many array elements

    if ($countSegs == 1) {
        $urlCityQuery = $urlCityArray[0];
    } 
    else if ($countSegs == 2) {

        $urlCityQuery  = $urlCityArray[0] . " " . $urlCityArray[1] . "', '";
        $urlCityQuery .= $urlCityArray[0] . "-" . $urlCityArray[1];

        // city1 city2, city1-city2
    }
    else if ($countSegs == 3) {

        $urlCityQuery  = $urlCityArray[0] . " " . $urlCityArray[1] . " " . $urlCityArray[2] . "', '";
        $urlCityQuery .= $urlCityArray[0] . "-" . $urlCityArray[1] . " " . $urlCityArray[2] . "', '";
        $urlCityQuery .= $urlCityArray[0] . " " . $urlCityArray[1] . "-" . $urlCityArray[2] . "', '";
        $urlCityQuery .= $urlCityArray[0] . "-" . $urlCityArray[1] . "-" . $urlCityArray[2];

        // city1 city2 city3, city1-city2 city3, city1 city2-city3, city1-city2-city3
    }
    else if ($countSegs == 4) {

        $urlCityQuery  = $urlCityArray[0] . " " . $urlCityArray[1] . " " . $urlCityArray[2] . " " . $urlCityArray[3] . "', '";
        $urlCityQuery .= $urlCityArray[0] . " " . $urlCityArray[1] . "-" . $urlCityArray[2] . " " . $urlCityArray[3] . "', '";
        $urlCityQuery .= $urlCityArray[0] . "-" . $urlCityArray[1] . "-" . $urlCityArray[2] . "-" . $urlCityArray[3] . "', '";
        $urlCityQuery .= $urlCityArray[0] . " " . $urlCityArray[1] . " " . $urlCityArray[2] . "-" . $urlCityArray[3];

        // city1 city2 city3 city4, city1 city2-city3 city4, city1-city2-city3-city4, city1 city2 city3-city4
    }
    else if ($countSegs == 5) {

        $urlCityQuery  = $urlCityArray[0] . " " . $urlCityArray[1] . " " . $urlCityArray[2] . " " . $urlCityArray[3] . " " . $urlCityArray[4] . "', '";
        $urlCityQuery .= $urlCityArray[0] . "-" . $urlCityArray[1] . "-" . $urlCityArray[2] . "-" . $urlCityArray[3] . "-" . $urlCityArray[4];

        // Notre-dame-de-lile-perrot
    }

    SELECT 'city' FROM Cities WHERE 'city' IN (" . $urlCityQuery . ") LIMIT 1;

如何以编程方式生成字符串模式的所有排列数组？

1 个答案: