Question

我试图从使用多个关键字的表中获取结果。它适用于单个关键字和两个关键字，但当我尝试查找超过2个关键字时，它不起作用。看看代码。

if (isset($_POST['keyword'])) {
    $keyword = $_POST['keyword'];
    // get rid of short words and spaces
    $keyword = trim( preg_replace("/[^a-z0-9']+([a-z0-9']{1,3}[^a-z0-9']+)*/i"," "," $keyword ") );
    $keyword = trim($keyword, ' ');
    // convert phrase to an array of keywords
    $keyword = explode(' ', $keyword);

    $query = $conn->query("SELECT title, url FROM pages WHERE keywords LIKE '%{$keyword[0]}%'");

    if (isset($keyword[1])) {
        //$query = $conn->query("SELECT title, url FROM pages WHERE keywords LIKE '%{$keyword[0]}%' OR '%{$keyword[1]}%'");
        $query = $conn->query("SELECT title, url FROM pages WHERE keywords LIKE '%{$keyword[0]}%' OR keywords LIKE '%{$keyword[1]}%'");
    }

    // why is it not reading the third keyword? is it a speed issue?    
    if (isset($keyword[2])) {
        $query = $conn->query("SELECT title, url FROM pages WHERE keywords LIKE IN('%{$keyword[0]}%','%{$keyword[1]}%','%{$keyword[2]}%')");
    }

    if (isset($keyword[3])) {
        $query = $conn->query("SELECT title, url FROM pages WHERE keywords IN('%{$keyword[0]}%','%{$keyword[1]}%','%{$keyword[2]}%','%{$keyword[3]}%')");
    }

    if (isset($keyword[4])) {
        $query = $conn->query("SELECT title, url FROM pages WHERE keywords IN('%{$keyword[0]}%','%{$keyword[1]}%','%{$keyword[2]}%','%{$keyword[3]}%','%{$keyword[4]}%')");
    }

我还希望它不能搜索像a，x等单个字符。

Answer 1

IN只是对列表中的所有元素进行完全相等的测试，它不像LIKE那样进行模式匹配。您需要将所有LIKE测试与OR结合使用。您可以动态执行此操作，而不是使用所有isset次调用。

$likes = implode(' OR ', array_map(function($keyword) use ($conn) {
    $keyword = $conn->real_escape_string($keyword); // Prevent SQL injection
    return "keywords LIKE '%$keyword%'";
}, $keywords));
$sql = "SELECT title, url FROM pages WHERE $likes";
echo "Query to execute: $sql";
$query = $conn->query($sql);

Answer 2

您可以将字符串分解为单个单词。下面的代码在每个空格后分割字符串。希望这有帮助

$parts = explode(' ', $string);
foreach ($parts as &$query) 
$sql =mysql_query("SELECT * FROM search_tbl where keywords like '%$query%'", $conn);

Answer 3

好吧，现在好了，感谢Barmar。我用MySQL格式创建了它。最后一件事，我希望它应该忽略空格，它应该忽略任何少于4个字符的关键字。我附上完整的代码。

aar

如何搜索多个关键字

3 个答案: