code: public function addForeignKey(string $name, $mapperClass, $onDelete = true, $onUpdate = false): Column
  	{
  		$table = $this->getTableData($mapperClass);
  
  		$constrait = new Constrait($name, $this, $table, $onDelete, $onUpdate);
  
  		$this->constraints[$constrait->name] = $constrait;
  		return $constrait->column;
  	}
docs: Nastavi cizi klic
  @param string $name
  @param string|Table $mapperClass klic uz musi byt v tabulce nastaven
  @param mixed $onDelete false => RESTRICT, true => CASCADE, null => SET null
  @param mixed $onUpdate false => RESTRICT, true => CASCADE, null => SET null
  @return Column