I'm having some difficulty with the SQL to populate the messages table in Chapter 6, page 192.
The SQL is included below, together with a screenshot of the resulting table.
There are two questions relating to the records where the subject is "Database Design"
- message_id 2 by user 2 asking for help "I'm creating a new database..."
- message_id 3 is a reply to the question "The number of tables in your database..." and has the parent_id 2 to indicate that. However, should the user_id here be 3, otherwise the original poster appears to be answering themselves?
The "Okay thanks" message is a reply to the reply, so should that have a parent_id of 3, or should it be linked to the overall parent message, message_id 2? The parent_id value 0 in the book doesn't seem right as this would suggest a new message (?)
SELECT * FROM forums;
SELECT user_id, username FROM users;
INSERT INTO messages (parent_id, forum_id, user_id, subject, body, date_entered) VALUES
(0, 1, 1, 'Question about normalization.', 'I''m confused about normalization. For the second normal form (2NF), I read...', UTC_TIMESTAMP()),
(0, 1, 2, 'Database Design', 'I''m creating a new database and am having problems with the structure. How many tables should I have?...', UTC_TIMESTAMP()),
(2, 1, 2, 'Database Design', 'The number of tables your database includes...', UTC_TIMESTAMP()),
(0, 1, 3, 'Database Design', 'Okay, thanks!', UTC_TIMESTAMP()),
(0, 2, 3, 'PHP Errors', 'I''m using the scripts from Chapter 3 and I can''t get the first calculator example to work. When I submit the form...', UTC_TIMESTAMP());