How to restrict number of columns to be update using oracle?

@dana 

To restrict the number of columns that can be updated in Oracle, you can create a trigger that checks the number of columns being updated before allowing the update to proceed. Here is an example of how you can achieve this:

1. Create a trigger that fires before an UPDATE operation on the table:

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CREATE OR REPLACE TRIGGER update_restrict_trigger
BEFORE UPDATE ON your_table
FOR EACH ROW
DECLARE
    l_column_count NUMBER;
BEGIN
    l_column_count := 0;
    
    IF UPDATING('COLUMN1') THEN
        l_column_count := l_column_count + 1;
    END IF;
    
    IF UPDATING('COLUMN2') THEN
        l_column_count := l_column_count + 1;
    END IF;
    
    -- Add more IF statements for each column you want to restrict
    
    IF l_column_count > 2 THEN
        RAISE_APPLICATION_ERROR(-20001, 'You can only update a maximum of 2 columns');
    END IF;
END;
/

1. Replace your_table with the name of the table you want to apply the restriction to.
2. Add additional IF statements for each column you want to restrict the update on.
3. Update the condition IF l_column_count > 2 to reflect the maximum number of columns you want to allow to be updated.
4. Replace the error message in RAISE_APPLICATION_ERROR with your desired error message.

After creating the trigger, it will prevent updates to the table if more than the specified number of columns are being updated.

Note: Be cautious when implementing this kind of restriction as it can have an impact on the normal operation of the application. It is recommended to thoroughly test the trigger in a development environment before deploying it to production.