[erlang-questions] Mnesia and primary keys
Patrick Collison
patrick@REDACTED
Mon Jan 22 13:01:54 CET 2007
Hi,
I'm new to both Erlang and Mnesia, and having trouble wrapping my
head around how Mnesia handles primary keys.
Suppose (in a RDBMS) I have two tables -- customers and orders. One
customer may have many orders. Ordinarily, of course, this would be
solved by having some a customer_id that each row in the order table
references. Bog-standard stuff.
As far as I can see (from reading the documentation I can find),
Mnesia doesn't assist you in any way in creating such primary keys
(as PostgreSQL, Oracle, MySQL (and pretty much any other systems)
do). Ensuring uniqueness, incrementing IDs, etc., seems to be left up
to the application programmer.
Am I missing the correct, "Erlang-style" manner of implementing this
kind of trivial cross-referencing, or am I unaware of facilities that
Mnesia does actually provide?
Cheers,
-Patrick
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