>>>>>I have a table where the key field is index a candidate index and field a want change is a regular index. I get the message
>>>>>

>>>>>Failed to update table,  Unique index violation
>>>>>

>>>>>The error number is 1884. How do I change the second value, i,e, from a "B" to an"A"?
>>>>
>>>>No, you want to update a field that is involved in Primary or Candidate index :-)
>>>>And that violates the rule.
>>>
>>>I know why I get the message, my question is there a way around the problem,
>>
>>Not if it violates the uniqeness of the key. You would have to make the index a regular index - not primary or candidate.
>
>But then how to I get rid of the original record, is there a way of programatically of temporarily changing the index and then changing it back afterwords.

No,
Even if you change it to regular and then try to make it back candidate or primary you will get an error again.
You could delete the original record, but you should make that index to be filtered index and to ignore deleted records or you should PACK the table before you insert new record (Grrr!)