Column updating problem

Hello,

Lets say I have two tables A and B which both have the same columns PK ,col1, col2, col3.
In table A there is only data in col1.The col2 and col3 columns will updated using the data from Table B (the tables will be joined using the PK column).

So here is the dilenma. How do i update Table A so that I retain the col1 values even though Table B may not have all the col1 values and still update Table A's col2 and col3 with the Table B data??

Table A

PK        col1       col2      col3
123       abc         ..           ..
234       def          ..           ..
567       ghi          ..           ..

Table B
PK        col1       col2      col3
123       abc         y          n
234                     n
567                     ..           y

Updated Table A
PK        col1       col2      col3
123       abc         y           n
234       def          n           ..
567       ghi          ..           y

Thanks,

Thanos Received on Mon Jan 23 2006 - 23:48:27 CST