＃1062 - 密钥1的重复条目“1” - 未找到重复条目

So when trying to add an autoincrement to a field it comes up with #1062 - Duplicate entry '1' for key 1 . I've tried removing the primary key and re-adding it and that works fine (which I assume wouldn't if there was duplicates?)So when trying to add an autoincrement to a fie