Updating from a column

On Monday 18 January 2010 11:31:57 am Bob Pawley wrote:

Hi

I have a table that has one column (pump1) controlled by a dbcheckbox. The
values can be True, False or null.

I want to insert a row of values into second table when column pump1 value
is 'True'. I don't want the trigger to insert a row when other columns of
the first table are updated or when the pump1 column value becomes 'False'.

I would appreciate any suggestions as to how to accomplish this.

Thanks in advance.

Bob

Create an INSERT, UPDATE trigger on table1. Have the trigger inspect the value
of pump1. You will need to guard against double entry on updates. So rough flow
is:

if TG_OP = 'INSERT' and NEW.pump1 = 't'
INSERT row second table
if TG_OP = 'UPDATE' and NEW.pump1='t'
if OLD.pump1 = 'f' or OLD.pump1 is NULL
INSERT row second table

--
Adrian Klaver
adrian.klaver@gmail.com