How can multiple fieldtype instances without a content column be attached to the same entry type and still be uniquely identifiable?
Since you're saving your data in a separate table, you basically need two fields within your custom table to help you identify which field &amp; element originally saved the content:


The element id (which you're already storing)
The field id (missing from your current setup)


You could even create an index on your custom table that would be a combo of those two fields.

In theory, you should be able to retrieve your data with a combination of the $field-&gt;model-&gt;id and $field-&gt;element-&gt;id.

When saving:

$attr['elementId'] = $field-&gt;element-&gt;id;
$attr['fieldId']   = $field-&gt;model-&gt;id;

$fieldRecord-&gt;setAttributes($attr);


When retrieving:

$fieldRecord = MyPlugin_FieldRecord::model()-&gt;findByAttributes(array(
    'elementId' =&gt; $field-&gt;element-&gt;id,
    'fieldId'   =&gt; $field-&gt;model-&gt;id,
));