SQL question

[jmmckee@xxxxxxxxxxxxxx]

I know how to do simple stuff in MS-SQL.  But, I need to make a database change
that I am not confident about.

The database is on an MS-SQL server.

I realize this is not a Midrange-specific question, and I apologize for that.

Basically, I need to populate two columns in one table with corresponding values
from another table.  But only under specific circumstances.

I do not want to change the first table's values if they are already populated. 
In the case of this database, there can be no valid dates prior to 11/01/1999. 
The database design is not mine.  The vendor is using two date-time columns,
one stores actual date and a time of zero.  The second stores the default date
1/1/1800 and the actual time.

What I have come up with, I present below.  It is incomplete.  I do not know how
to specify the second table properly.  The two tables are POST_PROCEDURE which I
want to selectively update, and POST_ANESTHESIA_TYPE, which has the data I need.

The two tables have a common column, CASE_NO.


Any help is appreciated.

Here is what I have come up with:

UPDATE POST_PROCEDURE p
  SET p.START_DATE = , p.START_TIME =
WHERE p.CASE_NO = a.CASE_NO
    AND p.PROCEDURE_ID = '131200'
   AND p.START_DATE < '11/01/1999'

John McKee