Php – Update schema for create longtext field on MySQL data base on symfony

I want to update MySQL field from text to longtext using Doctrine schema.

Now my code is like this:

/**
 *@var string
 *@ORM\Column(name="head_fa", type="string", length=1000, nullable=true)
 */
private $head_fa;

/**
 *@var string
 *@ORM\Column(name="head_en", type="string", length=1000, nullable=true)
 */
private $head_en;

/**
 *@var string
 *@ORM\Column(name="body_fa", type="text", length=1000, nullable=true)
 */
private $body_fa;

/**
 *@var string
 *@ORM\Column(name="body_en", type="text", length=1000, nullable=true)
 */
private $body_en;

and the problem is when i change this field to this code

/**
 *@var string
 *@ORM\Column(name="head_fa", type="string", length=1000, nullable=true)
 */
private $head_fa;

/**
 *@var string
 *@ORM\Column(name="head_en", type="string", length=1000, nullable=true)
 */
private $head_en;

/**
 *@var string
 *@ORM\Column(name="body_fa", type="text", nullable=true)
 */
private $body_fa;

/**
 *@var string
 *@ORM\Column(name="body_en", type="text", nullable=true)
 */
private $body_en;

and run "php app/console doctrine:schema:update –force" command on console it said that "Nothing to update – your database is already in sync with the current entity metadata." How to change this field to longtext on mysql database.

I do the same on different part of the project.
this is the code

/**
 * @ORM\Column(name="body", type="text", nullable=true)
 */
protected $body;

and after executing the "php app/console doctrine:schema:update –force" command on terminal this field is changed to longtext on MySQL database.