How to change the length of field settings?

Question

I have set once to a website a lenght limit to a field. And now the client wants to put more characters to that field.

I cannot change the maximum size from Drupal because I get the following error message:

There is data for this field in the database. The field settings can no longer be changed.

However there must be a solution. Shall I change it in database (the field is one implemented by the Field-collections module)?

Answer 1

Dylan Tack solution is the easiest, but personally I enjoy exploring the inner wards of Drupal's database to seen how things are managed down there.

So, assuming you have a text field which machine name is field_text of 10 characters you want to grow to 25:

• data will be stored in two tables: field_data_field_text and field_revision_field_text
• definition is stored in field_config for the storage data, and field_config_instance for each instance of this field (stuff like label).

Now let's do a little heart surgery.

1. Alter the data tables columns definitions:

   ALTER TABLE `field_data_field_text` 
   CHANGE `field_text_value` `field_text_value` VARCHAR( 25 ) 
   CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL;
   
   ALTER TABLE `field_revision_field_text` 
   CHANGE `field_text_value` `field_text_value` VARCHAR( 25 ) 
   CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL;
   

2. Change the definition column, this one is very tricky because it's stored in a BLOB, but that's not something that will stop you for doing this.

   • Dissect the guts of this BLOB thing:

   SELECT CAST(`data` AS CHAR(10000) CHARACTER SET utf8) 
   FROM `field_config` WHERE field_name = 'field_text';
   

   • This will give you something like:

   a:7:{s:12:"translatable";s:1:"1";s:12:"entity_types";a:0:{}s:8:"settings";a:2:
       {s:10:"max_length";s:2:"10";s:17:"field_permissions";a:5:
       //a lot more stuff...
   

   • This is a PHP serialized array, the interesting part is s:10:"max_length";s:2:"10";, this mean this array has a property named max_length (which name is a 10 characters string - hence the "s") which value is 10 (which is a 2 characters long string). It's pretty easy, isn't it?

   • Changing its value is as easy as replacing the s:2:"10" part by s:2:"25". Be careful: if your new value is longer you have to adapt the "s" part, for example putting 100 will be s:3:"100" as 100 length is 3.

   • Let's put this new value back in the DB, don't forget to keep the whole string.

   UPDATE `field_config` 
   SET data = 'a:7:{...a:2:{s:10:"max_length";s:2:"25";...}'
   WHERE `field_name` = 'field_text'
   

   • Flush your caches.

3. ???

4. PROFIT!

By the way, PhpMyAdmin has some setting to allow direct modification of BLOB columns, but why go the easy way?

PS: This can also save your life when putting some PHP code in views and getting a WSOD because of an error in your code.

Answer 2

This appears to be a limitation of the current text module. text_field_settings_form() has this comment: "@todo: If $has_data, add a validate handler that only allows max_length to increase.".

As a temporary workaround, you could comment out '#disabled' => $has_data in modules/field/modules/text/text.module, around line 77.

I couldn't find an existing issue for this specific case, but you might mention it on #372330.

Answer 3

In Drupal 7, I made modifications to 2 tables in phpmyadmin, and refreshed the cache.

1. "field_data_field_lorem": changed "field_lorem_value" to "longtext"
2. "field_config": changed "type" to "text_long"

Answer 4

Try this... this will update the field data type from TEXT to LONG_TEXT and update the max_length from 4000 to max long text length... hope this helps.

function my_module_update_1001(&$sandbox) { // Check if our field is already created. if (field_info_field('sample_text_field')) { db_query('ALTER TABLE field_data_sample_text_field CHANGE sample_text_field_value sample_text_field_value LONGTEXT'); db_query('ALTER TABLE field_revision_sample_text_field CHANGE sample_text_field_value sample_text_field_value LONGTEXT'); db_query("UPDATE field_config SET type = 'text_long' WHERE field_name = 'sample_text_field' ");

$field = array(
  'field_name' => 'sample_text_field',
  'type' => 'text_long',
  'cardinality' => 1,
  'settings' => array(
     'max_length' => 0,
  ),
);
field_update_field($field);    

} }

Answer 5

Although I think Dylan's solution is the cleanest (provided you erase the hack after updating the field), you can also just delete all content that uses the field. There are multiple ways of doing this.