2

This is a tricky problem but here is the jist of it. I have an entity that has a property called revision_id. Through hook_update_N I want to do 2 things.

  • Change the db column name to node_id
  • Convert the data in this db column from VIDs to NIDs

The code that takes care of this is...

function research_annotator_update_7100(&$sandbox) {

  // Change the db column.
  db_change_field(
    'research_annotator_annotation', 
    'revision_id', 
    'node_id', 
    array(
      'description' => 'The node the annotation belongs to.',
      'type' => 'int',
      'unsigned' => TRUE,
      'not null' => TRUE,
      'default' => 0,
    )
  );

  cache_clear_all();

  // Change revision ids into node ids.
  $arr_annotations = entity_load('research_annotation');

  foreach ($arr_annotations as $o_annotation) {
    $o_annotatedNode = node_load(NULL, $o_annotation->node_id);
    $o_annotation->node_id = $o_annotatedNode->nid;
    entity_save('research_annotation', $o_annotation);
  }
}

I also updated the entity property definition to represent the new node_id column...

research_annotator_entity_property_info() {

  $arr_propertyInfo = array();

  $arr_propertyInfo['research_annotation'] = array(
  'properties' => array(
    'node_id' => array(
      'label' => t('Revision'),
      'type' => 'integer',
      'description' => t('The revision id this annotation belongs to.'),
      'setter callback' => 'entity_property_verbatim_set',
      'required' => TRUE,
      'schema field' => 'node_id',
    ),
    ...snip

The problem is, when I run the update the first time, it gives me the following error...

Failed: PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'base.revision_id' in 'field list' ...

In the database, the changes have been made to the column but the data has not been converted. If I clear all caches and run the update again then everything works as planned. I suspect that because the entity cache is not cleared after the db column change, the error appears.

If this is the case, how can I ensure the entity cache is cleared immediately after db_change_field is called in the update hook?

0

3 Answers 3

0

cache_clear_all() with no arguments clears cache_block and cache_page only; entity and schema cache both live in the cache table, so clearing that bin explicitly should do the trick:

cache_clear_all(NULL, 'cache');

Or if you want to clear the specific entries:

cache_clear_all('entity_info', 'cache', TRUE);
cache_clear_all('entity_property_info', 'cache', TRUE);
cache_clear_all('schema', 'cache', TRUE);

I'm assuming you've already updated your hook_schema() implementation to match the new scheme, or implemented hook_schema_alter() for the same if you're doing this on behalf of a different module.

1
  • Unfortunately targeting the cache table in the cache_clear_all function does not work. Please see my answer. May 29, 2014 at 18:27
0

For whatever reason,

cache_clear_all(NULL, 'cache'); 

does not work in update hooks.

Instead you will have to clear cache table in a much more direct manner.

db_truncate('cache')->execute();
0

Holy... don't use the entity API in update hooks. That won't lead to anything good. Just use a direct SQL query, this can be done nice and easy with UPDATE {whatevertable} SET node_id = (SELECT vid FROM {node} WHERE nid = node_id) boom!

1
  • I just read this recommendation in the hook_update_N documentation. Is it recommended you only the database abstraction layer for CRUD functionality in update hooks? I ran update.php with my solution and it seemingly worked fine. Jun 4, 2014 at 14:23

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.