This option is not as safe as you can change table structure by accident.
To enter table editor select table, right click and choose Edit...
SET SERVEROUTPUT ON BEGIN UPDATE employees SET salary = 10000 WHERE employee_id = 9999; DBMS_OUTPUT.put_line('NO_DATA_FOUND Not Raised'); EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.put_line('NO_DATA_FOUND Raised'); END; / NO_DATA_FOUND Not Raised PL/SQL procedure successfully completed.
SQL SET SERVEROUTPUT ON BEGIN UPDATE employees SET salary = 10000 WHERE employee_id = 9999; IF SQL%ROWCOUNT = 0 THEN -- Manually raise the NO_DATA_FOUND exception.
Again, please be careful as you can change table structure by accident.
option: Table level comments are available in Comment tab. Please note this will apply all the changes you made to the table design. Now that you have put descriptions into the database it's time to think how to get them out in a usable format.
Describing schema elements can save you later from a lot of guesswork and errors - table and column names are not always self-explanatory. To view comments simply select table and comments will be visible in last column in columns grid on the first tab - Columns (wow, there's a lot of 'columns' in that sentence).
Data Definition Language (DDL) commands perform an implicit commit, which also confirms all outstanding DML changes in the current session.
If you decide you don't want to keep some uncommitted changes, you can throw them away using using the It's possible to update the base table associated with a view.
option: This will open column comments editor: If you chose the first option then you need to specify column from the drop down menu first.
Please note that each time you change column from the list your updates are lost so make your mind first and then start typing.