Call function within class without variable being used in PHP

Question

So I am basically re-doing some code on an existing system, mainly the database functions and I am putting them in a class rather than a function (currently the mysqli_connect DSN information is set in global variables and is being used every single time a query is being done which is why I am trying to clean this up but I am not trying to re-do this entire system all right now).

Current system has many PHP files that will include the main dbconnect.php file with a function of something like function db_query($query,$DSN){} and we have in almost every single other file the actual SQL query being written out and then passed off as db_query($query); and that is it.

I have moved over to something along the lines of the below code:

dbconnect.php

class Db {
    protected static $connection;

    function __construct() { 
        if (! isset($GLOBALS['DEBUG'])) { $GLOBALS['DEBUG'] = 0; }
    }

    public function connect() {
        if(!isset(self::$connection)) {
            self::$connection = new mysqli($GLOBALS['DSN']);
        }
        if(self::$connection === false) {
            return false;
        }
        unset($GLOBALS['DSN']); //unset so that login info is not roaming around anymore now that the connection has been established
        return self::$connection;
    }

    public function db_query($query) {
        $connection = $this->connect();
        $result = $connection->query($query);
        return $result;
    }
}

otherphpfile.php

include_once 'dbconnect.php';

(new Db());  //I have also tried new Db();

$query = "SELECT * FROM table;";
db_query($query); //I have to try to do it like this since 99.9% of the system is already using this method and I don't want to have to go through all the code and update it with something like:
$db = new Db();
$db->db_query($query);

I understand that $db = new Db(); $db->db_query($query); is correct but I am trying to do it like this new Db(); without a variable assigned to it because all of the other functions for dbconnect.php are written without a variable in front of the function call such as db_query($query); like they are right now without me having to go and update all of them to $db->db_query($query);.

I hope this makes sense and any suggestions would be great without compromising the benefit of using classes to begin with (AKA setting public static functions is just not worth it)

Thank you

@LawrenceCherone Thank you for your reply. I am sorry if I was confusing in my description, was trying to wrap out as I was in the office until 7pm on a Friday and wanted to go home lol. I understand that `$db = new Db(); $db->db_query($query);` is correct but I am trying to do it like this `new Db();` without a variable assigned to it because all of the other functions for `dbconnect.php` are written without a variable in front of the function call such as `db_query($query);` like they are right now without me having to go and update all of them to `$db->db_query($query);`. — ck1989, Jun 29 '19 at 02:13
It will be simpler to write a script to fix the code than try to do something the language is not designed to do. IMHO. — Nic3500, Jun 29 '19 at 03:45
You can do (new Db())->db_query(). But honestly i think this Is meaningless. You are giving your code new way of writing but it still works the same. You should rethink the architecture, not hunt ghosts. — slepic, Jun 29 '19 at 04:57
I would strongly advice to refactor your code and get rid of all these query functions. They look like a very bad idea and they might prevent you from using prepared statements. Check out this recent question: [When to use prepared statements?](https://stackoverflow.com/q/56813530/1839439) — Dharman, Jun 29 '19 at 15:00

score 0 · Answer 1 · answered Jun 29 '19 at 05:43

Part of refactoring is to update code. Honestly, any IDE would make replacing the usage of db_query() a breeze. You can replace the db_query( with (new Db())->db_query(. Since you are already storing the connection statically, I suggest making the class methods also static. Having something like Db::query(...) would be less redundant and more readable.

Call function within class without variable being used in PHP

1 Answers1