Question

I’m using MySQLi for a project (but could easily switch to PDO, read the edit at the bottom). What I want is to be able to process an associative array into an mysql query without typing every key/value pair manually. I know that might be simply put, but I’m still in a learning process when it comes to MySQLi/PDO. To make it clear what I mean here is an example:

Let’s say I have this associative array:

$data = array(
    'name' => 'Objective',
    'short_name' => 'OB',
    'generation' => 1
);

What I want is to create a query like this:

UPDATE signals SET ? = ? WHERE sid = '1'

And it to become a query like this (or instead of an UPDATE, an INSERT, SELECT etc.):

UPDATE signals SET
    name = 'Objective', 
    short_name = 'OB', 
    generation = 1 
WHERE sid = '1'

So basically my question is: is this possible with MySQLi or PDO itself? If it’s possible how would I have to do this?
I’ve read on preparing statements before executing, but it’s not getting to me yet. Hopefully someone can help me out.

Edit: I’m still very early into the project so i’m also fine with using PDO, but the same question remains. I did look into both PDO and mysqli, and I’m not sure how to do it with PDO either. So for the sake of the question i’ll add PDO to as a tag and to the question.

Answer 1

Here is a function that will take an input array and produce something you can drop straight into your query, as long as you are only updating a single table:

function array_to_pdo_params($array) {
  $temp = array();
  foreach (array_keys($array) as $name) {
    $temp[] = "`$name` = ?";
  }
  return implode(', ', $temp);
}

Now you can perform your PDO query like this:

// The data
$data = array(
  'name' => 'Objective',
  'short_name' => 'OB',
  'generation' => 1
);

// The parameter for the WHERE clause
$sid = 1;

// Build the query string
$query = "
  UPDATE `signals`
  SET ".array_to_pdo_params($data)."
  WHERE `sid` = ?
";

// Convert the data array to indexed and append the WHERE parameter(s) to it
$queryData = array_values($data);
$queryData[] = $sid;

$stmt = $db->prepare($query); // Obviously add the appropriate error handling

$stmt->execute($queryData);