Hi all,

i saw an explanation of junction table here:-
http://megocode3.wordpress.com/2008/...unction-table/
how correct is this explanation ?

but SELECT StudentName, RoomNumber
FROM StudentClassroom in this query

SELECT StudentName, RoomNumber
FROM StudentClassroom
JOIN Students ON Students.StudentID = StudentClassroom.StudentID
JOIN Classrooms ON Classrooms.ClassroomID = StudentClassroom.ClassroomID

doesn't seem to be correct is n't it?

I think it was used in IDMS or one of the early network DBs in the
1970's; we had it in the ANSI X3H2 NDL draft document that never saw
the light of day. The "parent-child" terminology was done as one way
pointers from one record to another record in a second file (think
IMS), but the junction tables had two-way pointers so you could
navigate in both directions.

I probably ought to put some of this history of bad terminology in one
of my books ...