Sql.php

<?php

namespace DesignPatterns\Structural\FluentInterface;

class Sql
{
 /**
 * @var array
 */
 private $fields = [];

 /**
 * @var array
 */
 private $from = [];

 /**
 * @var array
 */
 private $where = [];

 public function select(array $fields): Sql
 {
 $this->fields = $fields;

 return $this;
 }

 public function from(string $table, string $alias): Sql
 {
 $this->from[] = $table.' AS '.$alias;

 return $this;
 }

 public function where(string $condition): Sql
 {
 $this->where[] = $condition;

 return $this;
 }

 public function __toString(): string
 {
 return sprintf(
 'SELECT %s FROM %s WHERE %s',
 join(', ', $this->fields),
 join(', ', $this->from),
 join(' AND ', $this->where)
 );
 }
}