How to change Mysql to Mysqli

Question

Well, half of my project is using mysql plus I added a new function that uses mysqli which is generating some conflicts in the database. Either it saves what is in mysql or what is in mysqli. I tried to change to mysqli but could not make it work.

When using this mysql script only mysqli does not work

<?php

error_reporting(0);
ini_set(“display_errors”, 0 );

$conectar = mysql_connect("localhost","root","") or die ("Erro na conexão");
mysql_select_db("tcc")or die ("Base não encontrada");
?>

Already this only works mysqli and not mysql

<?php
	$servidor = "localhost";
	$usuario = "root";
	$senha = "";
	$dbname = "usuarios";
	
	//Criar a conexao
	$conn = mysqli_connect($servidor, $usuario, $senha, $dbname);
?>

I wanted to know how I change mysqli pro mysql already tried to remove the i mysqli no more right.

---

I changed my connection to mysqli_ and I can’t log in possibly because it’s not connecting to the database because the codes are in mysql_

The login code

<?php
session_start();
$usuariot = $_POST['usuario'];
$senhat = $_POST['senha'];
include_once("conexao.php");

$result = mysql_query("SELECT * FROM usuarios WHERE login='$usuariot' AND senha='$senhat' LIMIT 1");
$resultado = mysql_fetch_assoc($result);
//echo "Usuario: ".$resultado['nome'];
if(empty($resultado)){
	//Mensagem de Erro
	$_SESSION['loginErro'] = "Usuário ou senha Inválido";
	
	//Manda o usuario para a tela de login
	header("Location: index.php");
}else{
	//Define os valores atribuidos na sessao do usuario
	$_SESSION['usuarioId'] 			= $resultado['id'];
	$_SESSION['usuarioNome'] 		= $resultado['nome'];
	$_SESSION['usuarioNivelAcesso'] = $resultado['nivel_acesso_id'];
	$_SESSION['usuarioLogin'] 		= $resultado['login'];
	$_SESSION['usuarioSenha'] 		= $resultado['senha'];
	
	if($_SESSION['usuarioNivelAcesso'] == 1){
		header("Location: administrativo.php");
	}else{
		header("Location: usuario.php");
	}
}
?>

I tried to change the mysql_query and the mysql_fetch_assoc adding the i but it wasn’t enough I can’t log in