如何将参数器动态绑定到 SQL IN(） 子句

//Turns search value into array and counts elements. Or words in the string
$explode = explode(' ', $searchValue); //value = Array (chickens, are, fat)
$tags_cnt = count($explode); //value = 3
$cnt_q = NULL;
$s_cnt = NULL;
for ($i=0; $i<$tags_cnt; $i++) {
    //$cnt_q finds number of '?' needed for SQL
    $cnt_q = $cnt_q. '?';
    if ($i<$tags_cnt - 1) $cnt_q = $cnt_q.','; //value = ?,?,?
    //$s_cnt finds Number of 'S' for paramater binding
    $s_cnt = $s_cnt. 's'; //value = sss
}
//Turns the Array into comma separated string for Bindparam.
$tags=NULL;
    foreach ($explode as $tag) {
    $tags = $tags."'".$tag."',";
}
$tags = trim($tags, ",");// value = 'Chickens', 'are', 'fat'

//The IN clause = IN(?,?,?)
IN (".$cnt_q.")
//prepared binding statments = $stmt->bind_param('sss','chickens','are','fat');
$stmt = $conn->prepare($query);
$stmt->bind_param($s_cnt, $tags);

//retrive search value from ajax
$searchValue=$_GET["searchValue"];

//connect
$conn = new mysqli($host, $user, $password, $database);
if ($conn->connect_errno) {
    echo "Our apologies, having technical difficulties";
}
//assign tags, turn searchValue into a array by each word
$explode = explode(' ', $searchValue);
$tags_cnt = count($explode);
$cnt_q = NULL;
$s_cnt = NULL;
for ($i=0; $i<$tags_cnt; $i++) {
    $cnt_q = $cnt_q. '?';
    if ($i<$tags_cnt - 1) $cnt_q = $cnt_q.',';
    $s_cnt = $s_cnt. 's';
}
$tags=NULL;
foreach ($explode as $tag) {
    $tags = $tags."'".$tag."',";
}
$tags = trim($tags, ",");

//search by Tags 
$query = "  SELECT results.Title, results.tags
        FROM results
        INNER JOIN tags
        ON results.ID = tags.book_id 
        WHERE tags.tag 
        IN (".$cnt_q.")
        GROUP BY results.ID";

$stmt = $conn->prepare($query);
$stmt->bind_param($s_cnt, $tags);
$stmt->execute();
$results = $stmt->get_result();
    while($row = $results->fetch_array(MYSQLI_ASSOC)) {
        echo "Title: ";
        echo $row["Title"];
        echo "</br>";
        echo "Tags: ";
        echo $row["tags"];
        echo "</br></br> ";
    }

$stmt->close();
$conn->close();

试试这个，它应该可以正常工作：

$searchValue=$_GET["searchValue"]; //connect $conn = new mysqli($host, $user, $password, $database); if ($conn->connect_errno) { echo "Our apologies, having technical difficulties"; }

//assign tags, turn searchValue into a array by each word

$explode = explode(' ', $searchValue); $tags_cnt = count($explode);

$cnt_q = NULL; $s_cnt = NULL; for ($i=0; $i<$tags_cnt; $i++) {

$cnt_q = $cnt_q. '?'; if ($i<$tags_cnt - 1) $cnt_q = $cnt_q.',';

$s_cnt = $s_cnt. 's';

}

$tags[] = & $s_cnt;

for ($a=0; $a<$tags_cnt; $a++) { $tags[] = &$explode[$a]; }

//search by Tags

$query = " SELECT results.Title, results.tags FROM results INNER JOIN tags ON results.ID = tags.book_id WHERE tags.tag IN (".$cnt_q.") GROUP BY results.ID";

$stmt = $conn->prepare($query); call_user_func_array(array($stmt, 'bind_param'), $tags); $stmt->execute();

$results = $stmt->get_result(); while($row = $results->fetch_array(MYSQLI_ASSOC)) { echo "Title: "; echo $row["Title"]; echo "</br>"; echo "Tags: "; echo $row["tags"]; echo "</br></br> "; }

$stmt->close();

$conn->close();

尝试这段代码，不要做不必要的循环

$seachValue = isset($_GET['searchValue']) ? $_GET['searchValue'] : '';
if (!$seachValue) {
    exit('Empty search value');//Your error text
}
$values = explode(' ', $seachValues);
$size = count($values);
$markers = $params = array();
$markers = array_pad($markers, $size, '?');
$params = array_pad($params, $size, 's');
$mysqli = new mysqli($host, $user, $password, $database);
if ($mysqli->connect_errno) {
    exit('Our apologies, having technical difficulties');
}
$query = 'SELECT results.Title, results.tags
    FROM results
    INNER JOIN tags
    ON results.ID = tags.book_id 
    WHERE tags.tag 
    IN (' . implode(',', $markers) . ')
    GROUP BY results.ID';
$stmt = $mysqli->prepare($query);
if (!$smtp) {
    exit('Our apologies, having technical difficulties');//Your error text
}
$tags = array(implode($params));
for ($i = 0; $i < $size; ++$i) {
     $tags[] = &$values[$i];
}
call_user_func_array(array($stmt, 'bind_param'), $tags);
$stmt->execute();
$results = $stmt->get_result();
if ($results->num_rows > 0) {
    foreach ($row = $results->fetch_assoc()) {
        echo sprintf('Title: %s<br>Tags: %s<br><br>', $row["Title"], $row["tags"]);
    }
}
else {
    echo 'Nothing found';
}
$stmt->close();
$mysqli->close();