A Table with a timestamp as transaction date and primary key...

[Scott Fletcher]

I read some articles that the use of SQL's TIMESTAMP in a table is use
for recording the actual date/time that the row was inserted and for
row(s) that is/are updated.  I'm a little troubled by that because I
want a table with a timestamp in the first column to be the transaction
date which can be done by insert and that the timestamp not be altered
with the SQL update of any sort.  I also want the TIMESTAMP to be a
primary key.   So, what is my options?  Thanks...