iOS xcdatamodel newly added attribute has quotation mark <p>I just migrated my new data model and added a new attribute called "author_mail".However I discover at when I output my records:</p> <pre><code>attachments = "&lt;relationship fault: 0xd2459c0 'attachments'&gt;"; author = nil; "author_mail" = nil; &lt;-- ABNORMAL category1 = World; </code></pre> <p>I set the author_mail to string type but I don't think the author_mail should wrap with quotation mark. I don't know if it related to my migration but it does not output any error. Any clue where should I start look on? I found nothing on the internet. </p> <p>Result I want: </p> <pre><code>attachments = "&lt;relationship fault: 0xd2459c0 'attachments'&gt;"; author = nil; author_mail = nil; category1 = World; </code></pre> <p>Thanks everyone.</p>