[RBG7-L] - Re: When is a one to many form appropriate wtih 3 tables

[Michael Moser]

Hi David,   Thank you, that makes sense.   Just to clarify then in this context, in any normalized data schema situation any form with more than 2 tables is going to be a many-to-many form in R:Base 7.  This is true because 3 or more tables will always have "many (more than one) one-to-many" relationships.   yes?   Thanks, Michael Michael Moser EXAQ Micro Services www.exaq.com Phone: 916-966-8313 Fax: 916-966-8313  >>  Michael  In 7.x, the term "Many to Many" on the form  properties screen is  >>  not used in the classical relational database meaning. You  have MULTIPLE  >>  one to many relationships and so in 7.x you should use the "Many  to  >>  Many" setting (it really should read  >>  "Multiple One to Many" but who's  quibbling!)  David Blocker  >>  [EMAIL PROTECTED]  >>  781-784-1919  >>  Fax:  781-784-1860  >>  Cell: 339-206-0261 ----- Original Message -----  From: Michael Moser  To:  >>  RBG7-L  Mailing List  Sent: Saturday, March 12, 2005 11:38 AM Subject:  >>  [RBG7-L] - When is a one to many form appropriate wtih 3  tables  >>  Hi All,  >>  I just joined the list server so this topic may have been  addressed in  >>  the past.  If so I beg your indulgence one more time...  I am trying to  >>  understand when to use the one-to-many setting and when to  use the  >>  many-to-many setting in the form properties  >>  when using R:Base 7.1  forms  With two tables, A and B, with a one-to-many  >>  (<) relationship between the two (A<B), the form properties are set  to  >>  one-to-many and the form works correctly.  How ever if three tables are  >>  used (A, B, and C) such that:  >>  Table A has a Primary Key Table B has a Primary Key and a Foreign Key to A  >>  Table C has a Primary Key and a Foreign Key to B Table A and Table C have  >>  no common fields  Thus creating a one-to-many relationship between A and  >>  B, and a one-to-many    >>  relationship between B and C (A<B<C).  If a view AB was created from  >>  tables A and B, the view would also have a one-to-many relationship with  >>  table C (AB<C)  It seems that a form using A, B, and C would still be  >>  configured as  one-to-many but in fact it  >>  must be set to many-to-many in order to work  properly.  Setting the form  >>  to one-to-many with Tables A, B, and C  causes the correct record set to  >>  be displayed for B, but all records  are displayed for C.  So my question  >>  is this.  Can anyone provide an  >>  example of 3  tables that would use the one-to-many setting in a form?  >>  Perhaps my understanding of one-to-many is inaccurate and all forms using  >>  3  or more tables are many-to-many by definition, regardless of the  >>  relationships  between the tables.    >>  Thanks, Michael     >>  Michael Moser  >>  EXAQ Micro Services  >>  www.exaq.com  >>  Phone:  916-966-8313  >>  Fax: 916-966-8313