title: TYPO3 error: Incorrect integer value: '' for column at row 1
body: <p>I'm using TYPO3. I programmed an extension called 'Eventmanager', to manage events.</p>
  
  <p>After installing this extension, in Backend I can add/edit event-records. With each record there is a field called <em>end_time</em>, which is a <em>datetime-picker</em>, for choosing the date and time of the events.</p>
  
  <p>Today I edit an event-record. I deleted the value of this <em>end_time</em> field (to make it empty), and tried to save this record. But an error occurred during saving: </p>
  
  <p><em>2: SQL error: 'Incorrect integer value: '' for column 'event_end_time' at row 1' (tx_eventmanager_domain_model_event:13)</em></p>
  
  <p>The Settings in TCA is shown as follows:</p>
  
  <pre><code>    'endtime' =&gt; array(
          'exclude' =&gt; 1,
          'l10n_mode' =&gt; 'mergeIfNotBlank',
          'label' =&gt; 'LLL:EXT:lang/locallang_general.xlf:LGL.endtime',
          'config' =&gt; array(
              'type' =&gt; 'input',
              'size' =&gt; 13,
              'max' =&gt; 20,
              'eval' =&gt; 'datetime',
              'checkbox' =&gt; 0,
              'default' =&gt; 0,
              'range' =&gt; array(
                  'lower' =&gt; mktime(0, 0, 0, date('m'), date('d'), date('Y'))
              ),
          ),
      ),
  </code></pre>
  
  <p>and the definition in the file 'ext_tables.sql' is shown as follows:</p>
  
  <pre><code>event_end_time int(11) DEFAULT '0' NOT NULL
  </code></pre>
  
  <p>Can someone tell my what is the reason? How can I solve this problem?</p>