PDO Named parameters inside JSON - php

Question

I have data that should be escaped inside a JSON formatted string, so I'm using PDO's named parameters and PDO::Prepare to bind them.
Because JSON with it's apostrophes causes errors in the MySQL query, i have to use single quotes around it - although this causes the PDO::Prepare to ignore the named parameters inside the JSON, so it fails with SQLSTATE[HY093]: Invalid parameter number: parameter was not defined.
Any ideas how to work around this?
function send($_data) {
global $_SESSION;
global $dbApi;
#These are temporary debug variables:
$_SESSION['room_id'] = 1;
$id = 124;
$json = '"' . $id . '": {"user_id": ":email","data": ":data"}';
$query = "UPDATE `room_index` " .
"SET `data` = JSON_ARRAY_INSERT(`data`, '$[0]', '" . $json . "') " .
"WHERE `id` = :room_id";
$dbApi->query($query, array(':email' => $_SESSION['email'],
':data' => $_data,
':room_id' => $_SESSION['room_id']));
}
To explain the code a bit, :email ($_SESSION['email']) doesn't have to be a parameter, but it's cleaner this way. The main issue is :data ($_data) - that is user input straight from a textarea via JS.
$dbApi is a class with a proper query function, that looks like this:
function query($_query, $_params = array()) {
global $_DB; # <- Database connection object
$query = $_DB->prepare($_query);
if (! $query)
echo $_DB->errorInfo();
try {
$query->execute($_params);
} catch (PDOException $e) {
die( $e->getMessage() );
}
return $query;
}

Answer 1

There are 2 issues with the code.
1. JSON_INSERT is more appropriate.
As I'm inserting a named object into another object (the top level document), the JSON_INSERT offers such a syntax straight away
2. Using JSON_OBJECT instead of manually writing the JSON syntax
As my main issue was, that PDO doesn't replace single, or double quoted parameters, the solution was using JSON_OBJECT, which doesn't require double quotes as they are automatically generated later (my assumption) - but after PDO replaces the variables and also places single quotes around them.
New, tested code outputting valid JSON:
#Temporary, to avoid other unrelated issues
$_SESSION['room_id'] = 1;
$_SESSION['email'] = 'email#email.com';
$id = 123;
$json = 'JSON_OBJECT("user_id", :email, "data", :data)';
$query = "UPDATE `room_index` " .
"SET `data` = JSON_INSERT(`data`, :id, $json) " .
"WHERE `id` = :room_id";
$dbApi->query($query, [':id' => "$." . $id,
':email' => $_SESSION['email'],
':data' => $_data,
':room_id' => $_SESSION['room_id']]);