Read Access

Q:

The attribute birthday in our database table Friends allows NULL values:

INSERT INTO Friends VALUES
   (1, 'Jim', '1991-10-10')
  ,(2,  NULL, '2003-5-24')
  ,(3, 'Mick', '2001-12-30');

Starting our current application yields:

1, Jim, 1991-10-10
2, null, 2003-05-24
3, Mick, 2001-12-30

This might be confuses with a person having the nickname “null”. Instead we would like to have:

1, Jim, 1991-10-10
2, -Name unknown- , 2003-05-24
3, Mick, 2001-12-30

Extend the current code of sda.jdbc.intro.SimpleRead to produce the above result in case of nickname NULL values.

Hint: Read the documentation of wasNull().