loop on trigger

following your indication I found what I was looking for...Thank you.

I made a simple trigger/function that:
on insert check if a particular field is already on one table if not it
will procede to make the insert otherwise not.
But it goes on loop. Now just because I do not have experience, I'm
wondering if it possible to do it without going in loop, because if the
trigger is build up to get fired before the action and inside itself,
actualy, there is again the continuos of the action it is called again
and so on. There is a method to do without using the same table to
do the control and then the action? In other words interception an
insert to a specific table if the control is true to procede with the
action itself without hitting any loop?
TX
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Marco GERMONI            E-mail:mgermoni@uniautomation.it
Field Engineering Manager
Uniautomation S.r.l.               tel.+39-06-514221
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I-00142 Roma Italy                 GSM +39-348-9997186

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