Pl sql trigger if updating

03-Jan-2020 12:55

Triggers in different schemas can have the same name.

In addition to the requirement that trigger names be unique for a schema, there are other limitations on the types of triggers you can create.

The DML operation involves updating a million records.

You have no control over which type is fired first, and whichever type is fired after the first type will see any changes made by the first type, and that cascades down (third type sees changes made by the second type, and so on). There are a great many things you can do with triggers, whether they are based on DML statements or system events.

Finally, the mutating table error, ORA-04091 table owner.table_name is mutating, trigger/function may not see it has made DBAs trigger-happy in ways we would rather they not be exposed to. As a developer or DBA (or both), there is no such thing as having too many tricks up your sleeve.

This statement can be used with any interactive tool, such as SQL*Plus or Enterprise Manager.

When using an interactive tool, a single slash (/) on the last line is necessary to activate the 0) DECLARE sal_diff number; BEGIN sal_diff := :- :old.sal; dbms_output.put('Old salary: ' sal_diff); END; / keyword if you want the trigger to query or change the same table, because triggers can only do that after the initial changes are applied and the table is back in a consistent state.Because the trigger uses the clause, it might be executed multiple times, such as when updating or deleting multiple rows.