Trigger updating column
While that is a true statement, it ignores the fact that "their update" that is being honored is not, in any way, required to be the particular update you are wanting.
Trigger names do not need to be unique with respect to other schema objects, such as tables, views, and procedures.
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.
Returns a Boolean value that indicates whether an INSERT or UPDATE attempt was made on a specified column of a table or view.
UPDATE() is used anywhere inside the body of a Transact-SQL INSERT or UPDATE trigger to test whether the trigger should execute certain actions.
create table Employee( 2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 / Table created.