To set each author contract number to zero, simply leave off the WHERE clause.
The Oracle UPDATE statement locates one or more rows (or all the rows) in a table and sets one or more columns to the specified values.
As with the INSERT statement, the values must either match the columns data type or one that the database can implicitly convert.
PUT_LINE('empid successfully updated into emp_backup table'); END; The above trigger named ’emp_after_update’ will be initiated whenever ’empid’ column in ’emp’ table gets updated.
Now before updating ’empid’ column in ’emp’ table see the ’emp’ and ’emp_backup’ table records.
I'm trying to create a generic before update trigger which will compare all :old.column_values to all :new.column_values.
If the column_values are different, then I would like to log the change to a separate table. :new and :old are like bind variables to the trigger, they are not 'regular' variables. LOC); end; / I've been reading several related scenarios to this one.SQL Notice in the last update it indicated that x and y both were being updated (which they were), but the update didn't change the value (both x and y were 1 prior to the update which set them to 1). You can use updating (column) but it will only tell you that the column itself is being updated and not if the value has changed.If you need to determine if the value is changing, you'll still need to code comparison logic for :old and :new values.The basic format is: Let's go back to the AUTHOR table and look at some examples of Oracle updates.As with the INSERT section, I rolled back the changes to the original table. It works, but it won't tell you if the value changed, only that the column is being updated (even if the update doesn't change the value).