<?php

class MySQL{
    private $host;
    private $user;
    private $pass;
    private $dbName;

    public function __construct($host, $user, $pass, $dbName){
        $this->host = $host;
        $this->user = $user;
        $this->pass = $pass;
        $this->dbName = $dbName;
    }

    public function connect(){
        if(!mysql_connect($this->host, $this->user, $this->pass)){
            die('Erro de Conexão :'.mysql_error());
        }else{
            if(!mysql_select_db($this->dbName)){
                die('Erro de DB :'.mysql_error());
            }
        }
    }

    function insert($table, array $data){
        $value = array();
        foreach($data as $v){
            $value[] = "'".$this->escape($v)."'";
        }
        $strSQL = "INSERT INTO %s (%s) VALUES (%s) ";
        $strSQL = sprintf($strSQL, $table, implode(',',array_keys($data)), implode(',', $value));
        return $this->query($strSQL);
    }

    function update($table, array $data, $where){
        $strSQL = "UPDATE %s SET %s WHERE %s ";
        $value  = array();
        foreach ($data as $k => $v){
            $value[] = sprintf("%s = '%s'", $k, $this->escape($v));
        }
        $strSQL = sprintf($strSQL, $table, implode(',', $value),  $where);
        return $this->query($strSQL);
    }
    function delete($table, $where){
        $strSQL = "DELETE FROM %s WHERE %s";
        $strSQL = sprintf($strSQL, $table, $where);
        return $this->query($strSQL);
    }

    function numRows($strSQL){
        $query = $this->query($strSQL);
        return mysql_num_rows($query);
    }

    function fetchAll($strSQL){
        $result = array();
        $query  = $this->query($strSQL);
        while($row = mysql_fetch_assoc($query)){
            $result[] = $row;
        }
        return $result;
    }
    function fetchOne($strSQL){
        $query  = $this->query($strSQL);
        return mysql_fetch_assoc($query);
    }


    function query($strSQL){
        if(!$conn = mysql_query($strSQL)){
            die('Error '.mysql_error());
        }
        return $conn;
    }

    function escape($str){
        return mysql_real_escape_string($str);
    }
    function lastId(){
        return mysql_insert_id();
    }

}

$bd = new MySQL('localhost', 'root', '', 'videoaulasbrasil');
$bd->connect();

//PARA INSERIR
$data = array('categoria' => 'Informática', 'texto' => 'Tagtagatag');
$bd->insert('categorias', $data);


//PARA ALTERAR
$data = array('categoria' => 'Informática 2 ', 'texto' => 'Tagtagatag 2');
$bd->update('categorias', $data, "id = 5");


//PARA EXCLUIR
$bd->delete('categorias', "id = 5");


///Lista todo os itens
$strSQL = "SELECT * FROM categorias";
foreach ($bd->fetchAll($strSQL) as $k => $v){
        echo $v['categoria'];
}

//Retornar apenas uma linha
$strSQL = "SELECT * FROM categorias WHERE id = 4";
$row  = $bd->fetchOne($strSQL);
echo $row['categoria'];

//Total de Registro
$strSQL = "SELECT * FROM categorias";
echo $bd->numRows($strSQL);




?>