PHP将单选按钮和复选框值链接到联结表？

I have radio buttons and check boxes that I am trying to submit into a MySQL database using PHP. My issue is that these are going into junction forms and I also need to include the text inserts as a value on the table. Also, I honestly don't think I'm doing the radio buttons and check boxes right, something about Boolean structure?

I'm using MySQLi and just Notepad++.

My insert page has some radio buttons:

<input type="radio" name="audience" value="Youth" />Youth 
<input type="radio" name="audience" value="Teen" />Teen
<input type="radio" name="audience" value="Adult" />Adult

and some check boxes:

<tr><td><input type="checkbox" name="genre" value="1" />Action </td>
<td><input type="checkbox" name="genre" value="2" />Adventure </td></tr>
<tr><td><input type="checkbox" name="genre" value="3" />Comedy</td>
<td><input type="checkbox" name="genre" value="4" />Coming of Age</td></tr>

This is the PHP I have for the radio buttons:

if (isset($_POST['submit'])){
$audience= $_POST['audience'];
$sql = "INSERT INTO series (series_target_audience) VALUES 
('$audience')";
}

This code claims that it is working at this moment, but it is currently not actually depositing the values into the database at all.

You need to open a connection to MySQLi and then prepare the statement, bind parameter and execute it.

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli($host, $user, $pass, $db);
$mysqli->set_charset('utf8mb4');

if(isset($_POST['submit'])){
    $possibleRadioValues = ['Youth', 'Teen', 'Adult'];
    if(in_array($_POST['audience'], $possibleRadioValues, true)){
        $stmt = $mysqli->prepare('INSERT INTO series (series_target_audience) VALUES (?)');
        $stmt->bind_param('s', $_POST['audience']);
        $stmt->execute();
    }
}

Also worth noting is that you should validate the data coming from your HTML form, as it might not be what you expect. In this case I used a white list of values in the array.