framework: [L5.1] Migrations - Cannot change an existing column to type char

Trying to write a migration to change a column from VARCHAR to CHAR, but when I run the migration it throws the following error:

[Doctrine\DBAL\DBALException]
  Unknown column type "char" requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a list of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this err
  or occurs during database introspection then you might have forgot to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getMappedDatabaseTypes
  (). If the type name is empty you might have a problem with the cache or forgot some mapping information.

Here is what my up function looks like

 public function up()
    {
//        dd(\Doctrine\DBAL\Types\Type::getTypesMap());
        Schema::table('perk_word_search_boards', function (Blueprint $table) {
            $table->char('uuid', 36)->change();
        });
    }

Interestingly though if I add a new column of type char, the migration runs just fine.

About this issue

Original URL
State: closed
Created 9 years ago
Comments: 29 (14 by maintainers)

Commits related to this issue

Document unchangeable column types. As suggested by @GrahamCampbell in issue [#9636](https://github.com/laravel/framework/issues/9636) — committed to Kender2/docs by Kender2 8 years ago

Most upvoted comments

use Doctrine\DBAL\Types\StringType; use Doctrine\DBAL\Types\Type;

public function up() { if (!Type::hasType(‘char’)) { Type::addType(‘char’, StringType::class); }

Schema::table('tablename', function (Blueprint $table) {
    $table->char('field', 1)->nullable()->change();
});

}

+25

subratpalhar92 on May 8, 2020

Closing this as it’s not an issue with laravel/framework.

+10

GrahamCampbell on Aug 7, 2015

@subratpalhar92 Pretty sure that results in a VARCHAR column being created, not CHAR.

IllyaMoskvin on Jun 9, 2020

@phroggyy The function change() is included: http://laravel.com/docs/5.1/migrations#modifying-columns

However the documentation also says you need to have the package doctrine/dbal installed.

bobbybouwmann on Aug 7, 2015

@phroggyy Fair enough! Then the documentation needs some updating 😉

bobbybouwmann on Aug 7, 2015

I was having this exact problem trying to change $table->string(‘…’) to $table->longText(‘…’), it didn’t work in Laravel 5.0.

But trying out:

$table->string('column', 4294967295)->change();

updated the field to LONGTEXT(4294967295).

andfelzapata on Aug 2, 2016

This is possibly related, so I’ll post it here (please let me know if not, and I’ll create a new issue):

When trying to change a CHAR(36) column to a VARCHAR(50) column it changes the length but not the type. This column is also indexed, so it may be related to the above comment.

        Schema::table('table_name', function ($table) {
            $table->string('field_name', 50)->nullable()->change();
        });

I noticed that running a SQL statement also did not work, so it is probably a database limitation.

        DB::statement("
            ALTER TABLE `table_name`
            CHANGE `field_name` `field_name` VARCHAR(50) NOT NULL DEFAULT '0'
        ");

However, using the change() method still does not work with the indexes removed. Running the sql statement with the indexes removed did indeed change the field type to VARCHAR.

mikebronner on Jul 23, 2015

Changing ->char('name', 1) to ->string('name', 1) worked for me.

therealsmat on Mar 16, 2021

Thank @andfelzapata . I am editing an existing file. I managed to change the column type with out rollback. You can read it here: http://techcater.com/update-column-types-laravel-5-2/

dalenguyen on Aug 10, 2016