html + php提交表单无法插入mysql

Its my first try to PHP and I don't have much luck.

database is created in phpmyadmin with needed tables in same order I'm running Ubuntu 14.04.1 LTS 5.5.49-MariaDB-1ubuntu0.14.04.1 (Ubuntu) PHP 5.5.9-1ubuntu4.19 (cli)

Content of a.html:

<form method="post" action="aplicatie.php" name="ClaimForm" id="ClaimForm" autocomplete="on">
<fieldset>
    <legend>Completeaza detaliile tale:</legend>
    <div>
        <label for="numecont" accesskey="U">Numele contului</label>
        <input name="numecont" type="text" id="numecont" placeholder="ex: RSC_Alex" required />
    </div>
    <div>
        <label for="wn8overall" accesskey="U">WN8 Actual</label>
        <input name="wn8overall" type="text" id="wn8overall" placeholder="ex: 1800" required />
    </div>
    <div>
        <label for="wn8recent">WN8 Recent</label>
        <input name="wn8recent" type="text" id="wn8recent" placeholder="ex: 2700" required />
    </div>
    <div>
        <label for="email" accesskey="E">Email</label>
        <input name="email" type="email" id="email" placeholder="ex: admin@arcan.ro" pattern="^[A-Za-z0-9](([_\.\-]?[a-zA-Z0-9]+)*)@([A-Za-z0-9]+)(([\.\-]?[a-zA-Z0-9]+)*)\.([A-Za-z]{2,})$" required />
    </div>
    <label for="tara">Tara de resedinta</label>
    <input name="tara" type="text" id="tara" placeholder="ex: Romania" required />.
    <div>
        <label for="zileonline" accesskey="X">Cate zile pe saptamana poti fi activ incepand cu ora 20:00 (GMT+2)?</label>
        <select name="zileonline" id="zileonline" required="required">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
            <option value="7">7</option>
        </select>
    </div>
</fieldset>
<fieldset>
    <legend>Tancuri disponibile in garaj</legend>
    <div>
        <label for="tank10" accesskey="S">Numar de tancuri de nivel 10</label>
        <select name="tank10" id="tank10" required="required">
            <option value="0">0</option>
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
            <option value="7">7</option>
            <option value="8">8</option>
            <option value="9">9</option>
            <option value="10">10</option>
            <option value="peste10"> >10</option>
        </select>
    </div>
    <div>
        <label for="tank8" accesskey="C">Numar de tancuri de nivel 8</label>
        <select name="tank8" id="tank8" required="required">
            <option value="0">0</option>
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="peste5"> >5</option>
        </select>
    </div>
    <div>
        <label for="careclan" accesskey="T">Pentru care din clanuri doresti sa aplici?</label>
        <select name="careclan" id="careclan" required="required">
            <option value="ARCAN">ARCAN</option>
            <option value="ARKNE">ARKNE</option>
            <option value="ARKAN">ARKAN</option>
        </select>
    </div>
</fieldset>
<input type="submit" class="submit" id="submit" value="Vreau sa aplic" />

Content of aplicatie.php:

<?php
$mysql_host     = "localhost";
$mysql_username = "root";
$mysql_password = "pass";
$mysql_database = "aplicatii";

$conn= new mysqli ($mysql_host,$mysql_username,$mysql_password,$mysql_database);
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
} 
echo "Connected successfully";

$prepare="INSERT INTO `aplicatii1` (`wn8overall`,`wn8recent`,`email`,`zileonline`,`tara`,`tank10`,`tank8`,`careclan`,`numecont`) VALUES ($_POST['wn8overall'], $_POST['wn8recent'], $_POST['email'], $_POST['zileonline'], $_POST['tara'], $_POST['tank10'], $_POST['tank8'], $_POST['careclan'], $_POST['numecont'])";
if ($conn->query($prepare) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $prepare . "<br>" . $conn->error;
}
mysqli_close($conn);
?>

Try this:

 $servername = "localhost";  //host name

 $username = "username"; //username

 $password = "password"; //password

 $database = "dbname"; //database name

//mysqli prepared statement 

$conn = mysqli_connect($servername, $username, $password) or die("Connection failed: " . mysqli_connect_error());

mysqli_select_db($conn,$database) or die("Opps some thing went wrong");
$Wn8overall = mysqli_real_escape_string($_POST['wn8overall']);
$Wn8recent = mysqli_real_escape_string($_POST['wn8recent']);
$Email = mysqli_real_escape_string($_POST['email']);
$Zileonline = mysqli_real_escape_string($_POST['zileonline']);
$Tara = mysqli_real_escape_string($_POST['tara']);
$Tank10 = mysqli_real_escape_string($_POST['tank10']);
$Tank8 = mysqli_real_escape_string($_POST['tank8]);
$Careclan = mysqli_real_escape_string($_POST['careclan']);
$Numecont = mysqli_real_escape_string($_POST['numecont']);

$stmt = $conn->prepare("INSERT INTO aplicatii1 (wn8overall,wn8recent,email,zileonline,tara,tank10,tank8,careclan,numecont)  VALUES (?,?,?,?,?,?,?,?,?)");

$stmt->bind_param('sssssssss',$Wn8overall,$Wn8recent,$Email,$Zileonline,$Tara,$Tank10,$Tank8,$Careclan$Numecont);
            /*
                The argument may be one of four types:

                            i - integer
                            d - double
                            s - string
                            b - BLOB
                            change it by respectively
            */ 
$stmt->execute();

$row_count= $stmt->affected_rows;

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

 if($row_count>0){
    echo "New record created successfully";
 }
else{

}

As per your coding standard the Error lies in the following statements that when you are submitting the variable the submit button should have a corresponding name along with the insert statement with the usage of quotes and bacticks. You have not closed the form as per the Question you have provided

HTML Content:

<form method="post" action="aplicatie.php" name="ClaimForm" id="ClaimForm" autocomplete="on">
<fieldset>
    <legend>Completeaza detaliile tale:</legend>
    <div>
        <label for="numecont" accesskey="U">Numele contului</label>
        <input name="numecont" type="text" id="numecont" placeholder="ex: RSC_Alex" required />
    </div>
    <div>
        <label for="wn8overall" accesskey="U">WN8 Actual</label>
        <input name="wn8overall" type="text" id="wn8overall" placeholder="ex: 1800" required />
    </div>
    <div>
        <label for="wn8recent">WN8 Recent</label>
        <input name="wn8recent" type="text" id="wn8recent" placeholder="ex: 2700" required />
    </div>
    <div>
        <label for="email" accesskey="E">Email</label>
        <input name="email" type="email" id="email" placeholder="ex: admin@arcan.ro" pattern="^[A-Za-z0-9](([_\.\-]?[a-zA-Z0-9]+)*)@([A-Za-z0-9]+)(([\.\-]?[a-zA-Z0-9]+)*)\.([A-Za-z]{2,})$" required />
    </div>
    <label for="tara">Tara de resedinta</label>
    <input name="tara" type="text" id="tara" placeholder="ex: Romania" required />.
    <div>
        <label for="zileonline" accesskey="X">Cate zile pe saptamana poti fi activ incepand cu ora 20:00 (GMT+2)?</label>
        <select name="zileonline" id="zileonline" required="required">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
            <option value="7">7</option>
        </select>
    </div>
</fieldset>
<fieldset>
    <legend>Tancuri disponibile in garaj</legend>
    <div>
        <label for="tank10" accesskey="S">Numar de tancuri de nivel 10</label>
        <select name="tank10" id="tank10" required="required">
            <option value="0">0</option>
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
            <option value="7">7</option>
            <option value="8">8</option>
            <option value="9">9</option>
            <option value="10">10</option>
            <option value="peste10"> >10</option>
        </select>
    </div>
    <div>
        <label for="tank8" accesskey="C">Numar de tancuri de nivel 8</label>
        <select name="tank8" id="tank8" required="required">
            <option value="0">0</option>
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="peste5"> >5</option>
        </select>
    </div>
    <div>
        <label for="careclan" accesskey="T">Pentru care din clanuri doresti sa aplici?</label>
        <select name="careclan" id="careclan" required="required">
            <option value="ARCAN">ARCAN</option>
            <option value="ARKNE">ARKNE</option>
            <option value="ARKAN">ARKAN</option>
        </select>
    </div>
</fieldset>
<input type="submit" name="save_form" class="submit" id="submit" value="Vreau sa aplic" />
</form>

aplicatie.php

<?php
$host     = "localhost";
$username = "root";
$password = "pass";
$db = "aplicatii";
$con = new mysqli($host,$username,$password,$db);
if (mysqli_connect_errno())
{
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
echo "Connected successfully";
if(isset($_POST['save_form']))// Here the form method will executed if it is Submitted
{
$prepare="INSERT INTO `aplicatii1` (`wn8overall`,`wn8recent`,`email`,`zileonline`,`tara`,`tank10`,`tank8`,`careclan`,`numecont`) VALUES ('".$_POST['wn8overall']."','".$_POST['wn8recent']."','".$_POST['email']."','".$_POST['zileonline']."','".$_POST['tara']."','".$_POST['tank10']."','".$_POST['tank8']."','".$_POST['careclan']."','".$_POST['numecont']."'')";
$results = $con->prepare($prepare);// Prepare the Statements Here
$results->execute();// Execute the Statement Here
$results->close();// Close the Executed Statement Here
}
?>

AS per the New Standard of the mysqli.* the use of parametrized statements is alone better and advisable. But as per your siggestion of not going to run online you can use this method and hope it will crack your error. Share thought about this code after executing it.