Please Disable Your Browser Adblock Extension for our site and Refresh This Page!

our ads are user friendly, we do not serve popup ads. We serve responsible ads!

Refresh Page
Skip to main content
On . By CodimTh

in this post, I'll show you how to increase the length of field without losing data in drupal 8.


How to increase the length of field to 255 without losing data.

resize field


use hook_update_N() to chnage the length of field to 255 in database, configuration, and in storage schema. like the example below.



use Drupal\field\Entity\FieldStorageConfig;

 * @param $sandbox
function mymodule_update_90005(&$sandbox) {
  $entity_type = 'node';
  $field_name = 'field_description';
  $field_length = 255;

  $database = \Drupal::database();
  // Resize the main field data table.
  $database->query("ALTER TABLE {$entity_type}__{$field_name} MODIFY {$field_name}_value VARCHAR({$field_length})");
  // Resize the revision field data table.
  $database->query("ALTER TABLE {$entity_type}_revision__{$field_name} MODIFY {$field_name}_value VARCHAR({$field_length})");

  // Update storage schema.
  $storage_key = $entity_type . '.field_schema_data.' . $field_name;
  $storage_schema = \Drupal::keyValue('entity.storage_schema.sql');
  $field_schema = $storage_schema->get($storage_key);
  $field_schema[$entity_type . '__' . $field_name]['fields'][$field_name . '_value']['length'] = $field_length;
  $field_schema[$entity_type . '_revision__' . $field_name]['fields'][$field_name . '_value']['length'] = $field_length;
  $storage_schema->set($storage_key, $field_schema);

  // Update field configuration.
  $config = \Drupal::configFactory()
  $config->set('settings.max_length', $field_length);

  // Update field storage configuration.
  FieldStorageConfig::loadByName($entity_type, $field_name)->save();

  return t('Length of @entity-type.@field-name updated to @field-length', [
    '@entity-type' => $entity_type,
    '@field-name' => $field_name,
    '@field-length' => $field_length,


resized field



Submitted by Justin (not verified) on Fri, 12/13/2019 - 17:25 Permalink

I tried this out, but I'm still getting an error when i run my update saying that data exists. > [error] The SQL storage cannot change the schema for an existing field (field_special_information in product_entity entity) with data. It's in a custom entity, so I don't know if that is somehow making a difference.
Add new comment

Restricted HTML


Page Facebook

Become a patron

If you need some help or you search a Drupal freelancer don't hesitate to contact us.


Contact Us

All the content is FREE but I still need your help


Become a patreon