Therefore, do not create triggers that depend on the order in which rows are processed.
This feature lets the trigger see a global view of what the statement did, not just one row at a time.
This option is only allowed for an The name to give the new trigger.
This type of trigger also provides an additional correlation name for accessing the parent row that contains the nested table being modified. drop table tab1; create table tab1 (c1 clob); insert into tab1 values ('Some text.'); create or replace trigger trg1 before update on tab1 for each row begin dbms_output.put_line('Old value of CLOB column: '||: OLD.c1); dbms_output.put_line('Proposed new value of CLOB column: '||: NEW.c1); -- Previously, we couldn't change the new value for a LOB.
-- Now, we can replace it, or construct a new value using SUBSTR, INSTR...
Also, if global package variables are updated within a trigger, then it is best to initialize those variables in a , because a cursor must be opened for every execution of a trigger.
Although any trigger can run a sequence of operations either in-line or by calling procedures, using multiple triggers of the same type enhances database administration by permitting the modular installation of applications that have triggers on the same tables.
Each subsequent trigger sees the changes made by the previously fired triggers. The old values are the original values, and the new values are the current values, as set by the most recently fired trigger.
To ensure that multiple triggered actions occur in a specific order, you must consolidate these actions into a single trigger (for example, by having the trigger call a series of procedures). Deptno) AS Amp_list_ Emplist FROM Dept_tab d; The statement level triggers are useful for performing validation checks for the entire statement.
If the trigger fires before or instead of the event, the trigger can skip the operation for the current row, or change the row being inserted (for conditions, although the feature is not so useful for them since the condition cannot refer to any values in the table.
If multiple triggers of the same kind are defined for the same event, they will be fired in alphabetical order by name.
-- operations for a CLOB, or DBMS_LOB calls for a BLOB.