code: public function compile()
  	{
  		$sql = array("SELECT");
  
  		if ($this->is_distinct)
  		{
  			$sql[] = "DISTINCT";
  		}
  
  		if (empty($this->columns))
  		{
  			$sql[] = "*";
  		}
  		else
  		{
  			$sql[] = join(', ', $this->columns);
  		}
  
  		$sql[] = "FROM";
  		$sql[] = $this->table;
  
  		$sql = \array_merge($sql, $this->compileMixins());
  
  		if ($this->offset_num !== null)
  		{
  			$sql[] = "OFFSET {$this->offset_num}";
  		}
  
  		return join(' ', $sql);
  	}
docs: Compiles the query into raw SQL
  
  @return  string