Query unique (dynamic) or personalized?

Friend, I do not know if I understood very well what you want, but it seems that what you need is a persistent class with the database that already has the predefined methods where you use it in a simple way whenever you need it.

In case of this, I advise you to search for "CRUD" which means (Create = INSERT, READ = SELECT, UPDATE, DELETE) nothing less than you create a class with all the methods needed to work with the database.

Currently there are several ready-made tools that save you this work called #, I will list the ones I know (Doctrine ORM, Eloquent ORM, ADOdb Active Record) but there are a lot more than that and maybe you can find some can please you, I say this because to build a relationship with the database consistently effective requires a lot of work and dedication.

If you are interested in learning more about it, search for more about CRUD a> and ORM that will help you very.

In my time of learning I started with something simpler to understand more about CRUD and the PDO class (because it has many important security features that are worth learning).

Ex:

Configuration file: (Config.php)

/*
 * Definição do BD
 */
 define('HOST', 'localhost');
 define('USER', 'root');
 define('PASS', '');
 define('BD', 'data_bdTeste');
 define('DSN', 'mysql:host='.HOST.';dbname='.BD);

Connection File: (DBO.php)

class Dbo
{
/**
 * ---------------------------------
 *  Atributo de acesso à conexão
 *   estabelecida pelo sistema
 * ---------------------------------
 * @var $conn type arrayObject()
 */
static protected $conn;



/**
 * -------------------------------------------------
 * Método Construtor
 * responsável pela iniciação automática
 * após a instanciação ou herança da classe
 * -------------------------------------------------
 * @return $conn
 * @type arrayObject
 *
 */
public function __construct(){

    /**
     * verifica se a variável não está vazia
     *
     * Este método garante apenas uma conexão
     * com o banco de dados e nada mais!
     */
    if(is_null(self::$conn)){


        /**
         * Começa aqui a instanciação da Classe PDO
         * ------------------------------------------------------------------
         * ->Utilizamos aqui as constantes definidas no arquivo Config.php
         */
        self::$conn = new PDO(DSN, USER, PASS, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES UTF8"));

        /**
         * Define para que o PDO lance exceções caso ocorra erros
         * Preferencial para tratamento de erros
         */
        self::$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }

    //retorna a variável com o valor da conexão estabelecida
    return self::$conn;
   }
 }

CRUD File: (CRUD.php)

class CRUD extends Dbo
{
public $sql;

//Método para a consulta na tabela
/**
 * [listar]
 * @param  [type] $tabela   string
 * @param  [type] $coluna   string
 * @param  [type] $condicao string
 * @return [type]           array
 */
public function listar($tabela, $coluna, $condicao){
    return $this->sql = Dbo::$conn->prepare("SELECT {$coluna} FROM {$tabela} {$condicao}");
}

//Método para inserir registros na tabela
/**
 * [inserir]
 * @param  [type] $tabela   string
 * @param  [type] $coluna   string
 * @param  [type] $condicao string
 * @return [type]           boleano
 */
public function inserir($tabela, $coluna, $condicao){
    return $this->sql = Dbo::$conn->prepare("INSERT INTO $tabela ($coluna) VALUES ($condicao)");
}

//Método para o Update de registros na tabela
/**
 * [atualizar]
 * @param  [type] $tabela   string
 * @param  [type] $coluna   string
 * @param  [type] $condicao string
 * @return [type]           boleano
 */
public function atualizar($tabela, $coluna, $condicao){
    return $this->sql = Dbo::$conn->prepare("UPDATE $tabela SET $coluna WHERE $condicao LIMIT 1");
}

//Método para excluir registros
/**
 * [excluir]
 * @param  [type] $tabela string
 * @param  [type] $coluna string
 * @return [type]         boleano
 */
public function excluir($tabela, $coluna){
    return $this->sql = Dbo::$conn->prepare("DELETE FROM $tabela WHERE $coluna LIMIT 1");
  }
}

Usage: (index.php)

include "Config.php";
include "DBO.php";
include "CRUD.php";

$crud = new CRUD;
//LISTAR
$crud->listar('table', '*', 'WHERE id=:id ORDER BY id');
$crud->sql->bindValue(':id', 3805, PDO::PARAM_INT);
$crud->sql->execute();
print_r($crud->sql->fetchAll(PDO::FETCH_OBJ));

//Inserir
$crud->inserir('table', "email", ":email");
$crud->sql->bindValue(':email', '[email protected]', \PDO::PARAM_STR);
var_dump($crud->sql->execute());

//Atualizar
$crud->atualizar('table', "email=:email", 'id=:id');
$crud->sql->bindValue(':id',3805, PDO::PARAM_INT);
$crud->sql->bindValue(':email', '[email protected]', \PDO::PARAM_STR);
var_dump($crud->sql->execute());

//Deletar
$crud->excluir('table', 'id=:id');
$crud->sql->bindValue(':id', 3805, PDO::PARAM_INT);
var_dump($crud->sql->execute());

Hugs!