Hi Team,
When we do an implementation from Oracle to PostgreSQL in trigger for clause like :
updating(column_name) ==> (TG_OP='UPDATE' and OLD.column_name IS DISTINCT FROM NEW.column_name)
But this condition would mostly not be sufficient when we are updating any column and with similar value somehow.
Like : column_name OLD values is 2 and New values updates is 2.
In PG it would become (TG_OP="UPDATE' and 2 is DISTINCT FROM 2), Overall it becomes FALSE , so from conversion from ORACLE to PostgreSQL it doesn't give a clear picture for exact implementation for these UPDATING clause.
Now why I brought up this as I got into one of the implementations which made me crazy to implement.
Scenario :
Column c3 is right not updating to the same value of column, for some bypass implementation.
update table
c1 = 'abc',
c2 ='xyz',
c3=c3;
Inside trigger we have implementation like :
Oracle:
--THis block is being placed at the start of Trigger to bypass all other trigger blocks whenever we are updating column c3 , along with other columns.
IF UPDATING('C3') THEN
RETURN;
END IF;
If this column c3 is not placed in the update clause, then trigger would go through and execute other statements.
PostgreSQL:
We use the same method as :
IF TC_OP='UPDATE' and OLD.c3 is DISTINCT FROM NEW.C3 THEN
RETURN NEW;
END IF;
But here it won't ever go inside the IF clause and will never return out the start of trigger only. So technically not able to map the same Oracle fundamentals.
Is there any other method in POstgreSQL using which I can check which column is getting updated. Will just replace at least this clause with any other block.
Help would be really appreciated.