mysqli_select_db () expects parameter 1 to be mysqli, string given [duplicate]

Notice the error that gives you to the mysql_connect function:

  

Fatal error: Uncaught Error: Call to undefined function   mysql_connect () ....

This is because in the environment you are running it does not even exist. When we look at the documentation of this function we see that it has been removed from PHP 7.0.0 :

  

Warning This extension was deprecated in PHP 5.5.0, and it was removed   in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used (...)

The documentation itself tells you to switch to MySQLi or PDO . If you have a version PHP 7 or higher you have to change.

Your code with MySQLi looks like this:

$sql["host"] = "localhost";
$sql["usuario"] = "root";
$sql["senha"] = "arfito";
$sql["base"] = "digify";

//a conexão agora passa a levar a base de dados com quarto parâmetro
$conexao = mysqli_connect($sql["host"],$sql["usuario"],$sql["senha"], $sql["base"]);

mysqli_query($conexao, "SET NAMES utf8");
//--------------^ conexão é agora o 1º parametro do mysqli_query

$web = mysqli_fetch_array(mysqli_query($conexao, "SELECT * FROM settings ORDER BY id DESC LIMIT 1"));
//--------------------------------------^ conexão é agora o 1º parametro do mysqli_query

The mysql_fetch_array has been changed to mysqli_fecth_array , and the mysql_query has passed mysqli_query , but you also have to take the connection as the first parameter

Documentation for mysqli_connect and for mysqli_query

Correction to mysqli:

$sql["host"] = "localhost";
$sql["usuario"] = "root";
$sql["senha"] = "arfito";
$sql["base"] = "digify";
$conexao = mysqli_connect($sql["host"],$sql["usuario"],$sql["senha"]);
$select_database = mysqli_select_db($conexao, $sql["base"]);
mysqli_query($conexao, "SET NAMES utf8");

Useful links:

mysqli_select_db

mysqli_connect

mysqli_query