使用 PHP/MySQL 在 MySQL 数据库中存储多个标签？

Question

首先让我解释一下，我有这个脚本应该让用户输入多个用逗号分隔的标签，例如shoe, shirt, hat, glasses，并将每个标签存储在数据库中。

但由于某种原因，标签没有正确存储在数据库中。例如，当用户输入两个或多个标签时，它们都存储在同一行中，而不是在自己的行中显示它们，而且标签甚至没有输入到数据库中，只输入了一个空白行？

谁能给我几个例子，说明我需要在脚本中更改哪些内容才能解决此问题？

这是下面的mysql表。

CREATE TABLE questions_tags (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
tag_id INT UNSIGNED NOT NULL,
users_questions_id INT UNSIGNED NOT NULL,
PRIMARY KEY (id)
);

CREATE TABLE tags (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
tag VARCHAR(255) NOT NULL,
PRIMARY KEY (id),
UNIQUE('tag')
);

这是脚本。

<?php 
require_once ('./mysqli_connect.php');

if (isset($_POST['submitted'])) {
        $mysqli = new mysqli("localhost", "root", "", "sitename");
        $dbc = mysqli_query($mysqli,"SELECT questions_tags.*, tags.* FROM questions_tags, tags");
    if (!$dbc) {
        print mysqli_error($mysqli);
    }
$page = '3';

$tag = mysqli_real_escape_string($mysqli, $_POST['tag']);

$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"SELECT questions_tags.*, tags.* FROM questions_tags INNER JOIN tags ON tags.id = questions_tags.tag_id WHERE questions_tags.users_questions_id=3");
if(mysqli_num_rows($dbc) >= 0){

if (isset($_POST['tag'])){
    $tags = explode(",", $_POST['tag']);

    for ($x = 0; $x < count($tags); $x++){

$mysqli = new mysqli("localhost", "root", "", "sitename");
$clean_url = mysqli_real_escape_string($mysqli, $page);

$query1 = "INSERT INTO tags (tag) VALUES ('$tags[x]')";

if (!mysqli_query($mysqli, $query1)) {
    print mysqli_error($mysqli);
    return;
}

$mysqli = new mysqli("localhost", "root", "", "sitename");
$dbc = mysqli_query($mysqli,"SELECT id FROM tags WHERE tag='$tags[x]'");
    }
}

if (!$dbc) {
    print mysqli_error($mysqli);
}  else {
    while($row = mysqli_fetch_array($dbc)){
        $id = $row["id"];
    }
}

$query2 = "INSERT INTO questions_tags (tag_id, users_questions_id) VALUES ('$id', '$page')";

if (!mysqli_query($mysqli, $query2)) {
    print mysqli_error($mysqli);
    return;
}

echo "$tag has been entered";

    if (!$dbc) {
            print mysqli_error($mysqli);
    }
}
mysqli_close($mysqli);
}
?>

Answer 1

查看explode() 以分隔输入的标签列表。使用 foreach/for 循环遍历列表并分别插入每个标签。

最好的祝愿，
费边

Answer 2

替换这个：

$query1 = "INSERT INTO tags (tag) VALUES ('$tags[x]')";

用这个：

$query1 = "INSERT INTO tags (tag) VALUES ('" . $tags[$x] . "')";

顺便说一句，您需要保护sql injections 和XSS

更新：你还需要替​​换这个：

$dbc = mysqli_query($mysqli,"SELECT id FROM tags WHERE tag='$tags[x]'");

有了这个

$dbc = mysqli_query($mysqli,"SELECT id FROM tags WHERE tag='" . $tags[$x] . "'");

x 是一个变量...必须使用$x

Update2：questions_tags 代码必须在 for 循环内

这是固定代码

<?php
require_once ('./mysqli_connect.php');

if (isset($_POST['submitted'])) {
    $mysqli = new mysqli("localhost", "root", "", "sitename");
    $dbc = mysqli_query($mysqli,"SELECT questions_tags.*, tags.* FROM questions_tags, tags");
    if (!$dbc) {
        print mysqli_error($mysqli);
    }
    $page = '3';

    $tag = mysqli_real_escape_string($mysqli, $_POST['tag']);

    $mysqli = new mysqli("localhost", "root", "", "sitename");
    $dbc = mysqli_query($mysqli,"SELECT questions_tags.*, tags.* FROM questions_tags INNER JOIN tags ON tags.id = questions_tags.tag_id WHERE questions_tags.users_questions_id=3");
    if(mysqli_num_rows($dbc) >= 0){

        if (isset($_POST['tag'])) {
            $tags = explode(",", $_POST['tag']);

            for ($x = 0; $x < count($tags); $x++){

                $mysqli = new mysqli("localhost", "root", "", "sitename");
                $clean_url = mysqli_real_escape_string($mysqli, $page);

                $query1 = "INSERT INTO tags (tag) VALUES ('" . $tags[$x] . "')";

                if (!mysqli_query($mysqli, $query1)) {
                    print mysqli_error($mysqli);
                    return;
                }

                $mysqli = new mysqli("localhost", "root", "", "sitename");
                $dbc = mysqli_query($mysqli,"SELECT id FROM tags WHERE tag='" . $tags[$x] . "'");


                if (!$dbc) {
                    print mysqli_error($mysqli);
                }  else {
                    while($row = mysqli_fetch_array($dbc)){
                        $id = $row["id"];
                    }
                }

                $query2 = "INSERT INTO questions_tags (tag_id, users_questions_id) VALUES ('$id', '$page')";

                if (!mysqli_query($mysqli, $query2)) {
                    print mysqli_error($mysqli);
                    return;
                }

                echo "$tag has been entered";
            }
        }

        // is this needed?
        // if (!$dbc) {
        //   print mysqli_error($mysqli);
        // }
    }
    mysqli_close($mysqli);
}
?>