hook_update_N is not running I know there is a question hook_update_N not running but I checked its answers and it didn't help. I'm just learning developing modules for Drupal so maybe it's something really stupid but I have no idea...

My hook (in testModule4.install):

function testModule4_update_7001() {

$schema['testModule4_table'] = array(
    'description' =&gt; 'TODO: Description',
    'fields' =&gt; array(
        'main_id' =&gt; array(
            'description' =&gt; 'TODO: Description.',
            'type' =&gt; 'serial',
            'not null' =&gt; TRUE,
        ),
        'settings' =&gt; array(
            'description' =&gt; 'TODO: Description',
            'type' =&gt; 'text',
            'not null' =&gt; FALSE,
        ),
        'uid' =&gt; array(
            'description' =&gt; 'TODO: Description',
            'type' =&gt; 'int',
            'not null' =&gt; FALSE,
        ),
        'created' =&gt; array(
            'description' =&gt; 'TODO: Description',
            'type' =&gt; 'int',
            'not null' =&gt; FALSE,
        ),
        'changed' =&gt; array(
            'description' =&gt; 'TODO: Description',
            'type' =&gt; 'int',
            'not null' =&gt; FALSE,
        ),
    ),
    'primary key' =&gt; array('main_id'),
);

db_create_table('testModule4_table', $schema['testModule4_table']);

}


My module is working just fine. The schema_version of module in database is 0 but update.php just cannot see it. What can be the cause of that? :/ I was trying clearing cache and reenabling a module but without success. I just don't know where to search for source of the problem. If you need more data, just comment :/ .

Edit:

I created simple module:

testModule.module:

&lt;?php


function testModule_myform($delta = "") {

    $form['something'] = array(
        '#type' =&gt; 'markup',
        '#markup' =&gt; 'Something',
    );
    return $form;
}



/**
 * Implements hook_menu();
 */

function testModule_menu() {
    $items["test/test"] = array(
        'title' =&gt; 'testModule',
        'description' =&gt; 'TODO: Description',
        'page callback' =&gt; 'drupal_get_form',
        'page arguments' =&gt; array('testModule_myform'),
        'access callback' =&gt; TRUE,

    );
    return $items;
}


testModule.info:

name = testModule
description = Test module for Drupal experiments.
package = CustomTest
core = 7.x


testModule.install:

function testModule_update_7001() {
    drupal_set_message('It works!');
    print 'Show something!';
}


And it still ignores this hook... Is it officially a Drupal bug and I need to reinstall the whole Drupal? >_&lt;
The problem is upper/lowercase in your module name.

To be able to run update functions, your module must consist of lowercase characters only. Unlike all other hooks, those are detected through regexes and the way it's implemented isn't compatible with mixed case.