Update a table with a trigger after update

Question

I have two tables

 batch (batch_id,start_date,end_date,batch_strength,is_locked)
 sem (user_id,is_active,no_of_days)

I have executed the tr

Answer 1

Infinite recursion in this case because update trigger will do update operation on table batch and the same will triggered after execution of update statement inside em_sem_batch trigger itself.To prevent this add one column in table and in update statement of trigger update that column also to some value and add an if condition to check whether that column has that constant value if so avoid execution of update statement else execute update statement. See example below:

CREATE FUNCTION public.trigger_fuction()
    RETURNS trigger
    LANGUAGE 'plpgsql'
    NOT LEAKPROOF
AS $BODY$
BEGIN
  IF NEW.data_replicated=true THEN
    UPDATE sample SET data_replicated=false WHERE id=NEW.id;
    raise notice 'changed data replicated of sample with id as %',NEW.ID;
  END IF;
  RETURN NEW;
END;
$BODY$;


CREATE TRIGGER data_replication_trigger
  AFTER UPDATE
  ON sample
  FOR EACH ROW
  EXECUTE PROCEDURE trigger_fuction();

In this example sample table has data_replicated boolean field which will be updated when trigger is executed.