Constraint, Rule, or Trigger?

I've had experience with SQL and database design, but not much with rules

&

triggers. What's the best method to accomplish the following it PGSQL:

_Table A_ has a boolean field 'status'

_Table B_ has a 1-1 child relationship to Table A.

The rule, trigger, or contraint would have to enforce that: no record

could

be created in B if the 'status' field was false in the parent record in

A

Just point me in the right direction.
Thanks

Well start here: http://www.postgresql.org/idocs/index.php?plpgsql.html
and in particular look at
http://www.postgresql.org/idocs/index.php?plpgsql-trigger.html

Also, if you have the source tree available, look at

<path-to-pgsql-source>\src\pl\plpgsql\test\triggers.sql

for lots of examples.

Hope this helps,

-- Joe

on 8/10/01 10:53 PM, Joe Conway at joseph.conway@home.com wrote:

I've had experience with SQL and database design, but not much with rules

&

triggers. What's the best method to accomplish the following it PGSQL:

_Table A_ has a boolean field 'status'

_Table B_ has a 1-1 child relationship to Table A.

The rule, trigger, or contraint would have to enforce that: no record

could

be created in B if the 'status' field was false in the parent record in

A

Just point me in the right direction.
Thanks

Well start here: http://www.postgresql.org/idocs/index.php?plpgsql.html
and in particular look at
http://www.postgresql.org/idocs/index.php?plpgsql-trigger.html

Also, if you have the source tree available, look at

<path-to-pgsql-source>\src\pl\plpgsql\test\triggers.sql

for lots of examples.

Hope this helps,

-- Joe

Thanks, it does.

--
Randy Perry
sysTame
Mac Consulting/Sales