The previous chapter showed you how to use
INNER JOIN and
LEFT JOIN to retrieve information stored in multiple tables. You also learned how to link existing tables by adding an extra column to the child table and updating each record individually to insert a foreign key. However, most of the time, you'll want to insert data simultaneously in both tables. That presents a problem, because
INSERT commands can operate on only one table at a time. You need to get around this restriction by constructing scripts that handle the
INSERT operations in the correct sequence, starting with the parent table, so that ...