POST Data not inserting into sql table

Question

I am using a form. (I wanted the message text as a text area but changed back to normal text to see if this was the problem)

This is the form I am using

<form name="addmessage" method="POST" action="addmessage.php" >
    <input type="text" name="message_title" id="message_title">Message Title</input>
    <input type="text" name="message_text" id="message_text">Message</input>
    <input type="submit" name="submit" value = Add> 
  </form>

Below is the PHP code. I understand i need to protect against sql injection however, i can do this later.

    <?php
include_once("config.php");
if(isset($_POST["message_title"]) && strlen($_POST["message_title"])>0) 
    {
$message_title=$_POST['message_title'];
$message_text=$_POST['message_text'];
session_start();
$barber_id = $_SESSION['barber_id'];

$insert_row = $mysqli->query("INSERT INTO messages(barber_id,message_title,message_text) VALUES('".$barber_id."','".$message_title."',".$message_text.")");

}
else

{
    //Output error
    header('HTTP/1.1 500 Error You have left it blank');
    exit();
}

header("location:messages.php");
?>  

If manually enter data using phpMyAdmin, I can get it to display using the code below.

include_once("config.php");
        session_start();
        $barber_id = $_SESSION['barber_id'];
        $results = $mysqli->query("SELECT * FROM messages WHERE barber_id ='$barber_id' ");
            //get all records from  table
            while($row = $results->fetch_assoc())
            {
                $prices_id = $row['prices_id'];
                echo '<div data-role="collapsible">';   
                echo '<h1>';
                echo '   Message Title: ';  
                echo $row['message_title'];
                echo '</a>';
                echo '</h1>';
                echo '<p>';
                echo $row['message_text'];
                echo '<a href="delete_price.php?prices_id='.$prices_id.'"  class="ui-btn ui-icon-delete "> Delete</a></div>';
            }
  $mysqli->close();
    ?>

Answer 1

At $insert_row = $mysqli->query("INSERT INTO messages(barber_id,message_title,message_text) VALUES('".$barber_id."','".$message_title."',".$message_text.")");

you should write

$insert_row = $mysqli->query("INSERT INTO messages(barber_id,message_title,message_text) VALUES('".$barber_id."','".$message_title."','".$message_text."')");

Everytime you pass a String or other non int values you must pass them like that: 'xx', otherwise mysql will see it as query param and it crashes.