Plsql trigger if updating
For example, a table and a trigger can have the same name (however, to avoid confusion, this is not recommended). If a triggering statement includes a column list, the trigger is fired only when one of the specified columns is updated.
If a triggering statement omits a column list, the trigger is fired when any column of the associated table is updated.
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.
Trigger Evaluation Order 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.
There are two types of triggers based on the which level it is triggered.
A column list cannot be specified for statement trigger is fired again.
The rollback to savepoint does not undo changes to any package variables referenced in the trigger.
Because the trigger uses the clause, it might be executed multiple times, such as when updating or deleting multiple rows.
You might omit this clause if you just want to record the fact that the operation occurred, but not examine the data for each row.