Question

I have a table

____________________________________________________________
|                         Message                           |
|___________________________________________________________|
| Sender  |  Message    |    Receiver       |   message_id  |   
| John    | How Are You?|      Will         |       1       |
|_________|_____________|___________________|_______________|

In Will computer I am showing as follows

Message By:John
Message:How Are You?

Now Suppose John Deleted this message But i can’t remove the record because Will has not yet deleted.Therefore I am running a update query

Update Message Set Sender='' where message_id=1;

But after doing that in will computer message changes as follows

 Message By:                    //Because i have changed sender to null
    Message:How Are You?

Now how can i overcome this error of not getting desired output

Answer 1

Add seperate boolean ReadBySender and ReadByReciever columns and update those rather than the actual sender/reciever