Oracle if updating trigger dogloversdatingsite com
UPDATE bank_transactions SET txn_number = 'NEWTXN8080' WHERE txn_id = 1; UPDATE bank_transactions SET txn_number = 'NEWTXN9595' WHERE txn_id = 2; -- output 1 rows updated. Dhaval Dadhaniya is a software engineer by profession and reader/writter by passion.
CREATED_DATE); END; --Inserting values INSERT INTO BANK_TRANSACTIONS values ('1','TXN1234','Peter Thomas','12-MAY-2017','HR',sysdate); INSERT INTO BANK_TRANSACTIONS values ('2','TXN9999','Jemes Patel','10-JUN-2016','HR',sysdate); select * from BANK_TRANSACTIONS; --updating values.
A mutation table is defined as a table that is changing.
But in dealing with triggers, it is a table that has the possibility of changing.
In many cases, the cause of this error is due to code within a trigger that looks at or touches the data within the table the trigger is being called or invoked from.
The reason Oracle raises this error is related to one of Oracle's primary strengths as a relational database management system.
This can also happen when a trigger on a parent table causes an insert on a child table referencing a foreign key.
The particular strength in question here is that of having a read consistent view of data.
It is worthwhile to note that this ORA-04091 error occurs not only in the "pure" database development environment, but also in the Oracle tools type of development environment such as Oracle SQL*Forms.
Mutating table errors only impact row level triggers.
But to use a statement level trigger, some data may need to be preserved from each row, to be used by the statement level trigger.
Each new release of the Oracle database reduces the impact of the mutating table error on triggers and they are much less of a problem with Oracle9i and above.