Relationship question

[Phil]

I am learning Access, and have one question on relationships. How does one
handle establishing a relationship that could be one-to-many, going either
way between two tables? Example: One table lists home addresses. Another
table lists kinds of correspondence (letters sent). There is a 3rd table
with letter information (date, topic, etc.). There could be 100 addresses
in one table and 10 kinds of letters in another table. There could be one
kind of letter going to many addresses, or, one address receiving many kinds
of letters. How is this dealt with? Or is this problem evidence that
something is not set up right with the tables?

Thank you,

- Phil

[Rick Brandt]

"Phil" <p.*****@comcast.net> wrote in message
news:ojJCc.176790$Ly.56856@attbi_s01...

I am learning Access, and have one question on relationships. How does one
handle establishing a relationship that could be one-to-many, going either
way between two tables? Example: One table lists home addresses. Another
table lists kinds of correspondence (letters sent). There is a 3rd table
with letter information (date, topic, etc.). There could be 100 addresses
in one table and 10 kinds of letters in another table. There could be one
kind of letter going to many addresses, or, one address receiving many kinds
of letters. How is this dealt with? Or is this problem evidence that
something is not set up right with the tables?

What you're describing is a Many-To-Many relationship and it requires a third
table where each record is a combination of Primary Keys from your current
tables.
--
I don't check the Email account attached
to this message. Send instead to...
RBrandt at Hunter dot com

[Bernard Peek]

In message <2k*************@uni-berlin.de>, Rick Brandt
<ri*********@hotmail.com> writes

"Phil" <p.*****@comcast.net> wrote in message
news:ojJCc.176790$Ly.56856@attbi_s01...

I am learning Access, and have one question on relationships. How does one
handle establishing a relationship that could be one-to-many, going either
way between two tables? Example: One table lists home addresses. Another
table lists kinds of correspondence (letters sent). There is a 3rd table
with letter information (date, topic, etc.). There could be 100 addresses
in one table and 10 kinds of letters in another table. There could be one
kind of letter going to many addresses, or, one address receiving many kinds
of letters. How is this dealt with? Or is this problem evidence that
something is not set up right with the tables?

What you're describing is a Many-To-Many relationship and it requires a third
table where each record is a combination of Primary Keys from your current
tables.

When you need to create a link table it's worth taking some time to look
closely at the data structure. Quite often those link tables correspond
to some real-world object and you find that they need more fields than
just the keys of the other tables involved.

--
Bernard Peek
London, UK. DBA, Manager, Trainer & Author. Will work for money.