I am trying to develop a trigger function that searches for lines with
particular properties. I have two or more lines joining at a point but only one
line exiting from that point. I want to check that the size of the outgoing
(exiting) line is always not smaller than incoming lines.
Take such data as example:
line_name from_point to_point size
line1 p1 p2 2
line2 p10 p2 3
line3 p2 p7 1
line4 p7 p8 3
Lines Line1 and Line2 join at point p2 (to_point), therefore line3 should have
size at least equal to 3.
Tried to use this select statement but doesnt work, could anyone give me an idea
Select link_name, diameter, from_node, to_node from links as ends where
ends.diameter< links.diameter;
or even
SELECT from_node from links as dstream intersect SELECT to_node from links
as previo ;
Thank you
Broun Uganda
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