> I started to use PHP with MySQL last december. > Personal use: list of inhabitants of a town in the 15th century > > Problem is the following: one person has an arbitrary number of children. > It is heavy to have fields child1,child2,child3,...,childn containing the row > number of each child especially if the number of children is variable. > > When I played with Commodore VIC20 I used to put pointers to records in a > string in the form pointer1,pointer2,...,pointern in a string. > > I think of using explode and implode to put all the record numbers of the > children in one varchar field. > > If someone have a better idea?
NOOOOO!!! Don't do that... that's horrible database design. :) You should/could have a separate table for children. It'll have 3 fields 1: Unique ID for each child 2: ID of parent 3: Name of child plus whatever other information you decide to keep on children. Notice how extensible this is. You can have an unlimited number of children for each parent. You could treat this like a forum, too, and use a single table. 1. Unique id for each person 2. ID of parent 3. Name etc... Where, column 2 would be NULL (or empty) if the person is at the "top" of your chain (i.e. their parents aren't in the database). Everyone under them (their children, grandchildren, etc) would be in the same table and have column 2 as the ID of their parent (coming from the same table). Confusing? I hope not, but ask away if it is... :) ---John Holmes... -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
