On Tuesday 22 January 2008 15:01:07 Jean Hollis Weber wrote: > Dan Lewis wrote: > > I need an example of a n:n relationship in a database preferable a > > simple one. I understand 1:1 and n:1 rather well. Or, if someone else can > > give me an example, that would be appreciated as well. > > I hope to have the Introducing Base chapter completed before the end > > of the month. But I need this information to do it. > > Mariano Casanova said this in his draft mid-level Base tutorial > (which I can't find on the OOoAuthors website, so perhaps he > hasn't put it there yet): > > "Many to many relationships can not be performed without the use > of an intermediate table. For example, one author could write one > or more books; at the same time, one book could be written by > several authors (in collaboration). In order to keep track of > this, you will need a simple table -- maybe with only two columns > -- between the 'Author' and 'Titles' tables that can record all > the combinations (pairs) of book and author. Every time you > encounter a n..n cardinality, you now that you will be using an > intermediate table with 1..n cardinal relationships." > > --Jean
Thanks! I will use that. Dan
