Named placeholders in with PDO mySQL causing server error - php

Question

I'm a novice when it comes to mySQL, and even more so when it comes to PDO. I'm trying to create some simple insert code but I keep getting a server error. I have a feeling it has to do with defining $STH twice. Here's my code:
$dsn = "mysql:host=localhost;dbname=Menu_Items";
$user = "root";
$pass = "root";
// Connect to database
try{
$DBH = new pdo($dsn, $user, $pass);
}
catch(PDOException $e) {
echo $e->getMessage();
}
// Define user input as $food
$name = $_POST['food'];
$STH->bindParam(':name', $name);
// Insert user input into table
$STH = $DBH->prepare("INSERT INTO foods ( name ) VALUES ( :name )");
$result = $DBH -> query($STH);
if($result){
echo("<br>Input data is succeed");
}else{
echo("<br>Input data is fail");
}
This php code is connected to a simple html form:
<form id="menu_input" name="menu_input" method="post" action="insert.php">
<table>
<thead>Enter a new item</thead>
<tr>
<th><label for="food">Food</label></th>
<td><input type="text" name="food" id="food" placeholder="Food Name" required></td>
</tr>
<tr>
<td><input type="submit"></td>
</tr>
</table>
</form>
I've been doing research but just having a little difficulty getting it to work. Thoughts?

Answer 1

First create/get the object/instance then use its methods; not the other way round.
// Insert user input into table
$STH = $DBH->prepare("INSERT INTO foods ( name ) VALUES ( :name )");
$STH->bindParam(':name', $name);
$STH->execute();
and (nit-picking mode: on) there's no need for the variable $name
// Insert user input into table
$STH = $DBH->prepare("INSERT INTO foods ( name ) VALUES ( :name )");
$STH->bindValue(':name', $_POST['food']);
$STH->execute();
will do, and so would
// Insert user input into table
$STH = $DBH->prepare("INSERT INTO foods ( name ) VALUES ( :name )");
$STH->execute(array('name'=>$_POST['food']));

Answer 2

Use bindValue instead of bindParam, because you are binding value, not parameter. Call bindValue after prepare statement:
...
$name = $_POST['food'];
// Insert user input into table
$STH = $DBH->prepare("INSERT INTO foods ( name ) VALUES ( :name )");
$STH->bindValue(':name', $name);
$result = $DBH->query($STH);
...

Answer 3

Named placeholders has nothing to do with your problem.
And they aren't "best bet". It's just a syntax sugar, quite unnecessary one.
Your problem is not a named placeholder but syntax which you have got out of nowhere.
Always read the manual page on the function you are using. query() method doesn't support placeholders.
Always read tag wiki before asking a question. There you can see the proper example.
Please read Stackoverflow tag wiki on PDO I linked above and use code from there. Both for connecting and query execution.
You have to set up error reporting to see the errors. Otherwise there is noway to know what is wrong with your code.