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From Tony Giaccone <>
Subject Re: Accessing a sequence number in java
Date Thu, 24 May 2018 16:59:34 GMT
Oh, the tangled web we weave, when first we practice to deceive...

Why isn't it the primary key?  Because this id represents a value that's
unique in another database, and it's really a foreign key to a database
that we don't have access to.  A better design would be  to use this value
as the key to our table, but historically it wasn't done that way so... now
I'm going to dummy it up and I'd like it to be unique because it is
replicated in our schema and I really don't want collisions.

Another thought was to map the key from the table to the "foreign" key
value, but there are problems with the optics of that choice when talking
about what I did to the target audience.

Sadly, it needs to be a long, so subbing in a uuid, or a string really
isn't a good choice.  ON the other hand maybe using apache string utils to
generate a random large string and then taking the hash of that string
might yield something random enough.

Thank you all for your assistance.


On 2018/05/23 20:53:29, Ken Anderson <> wrote:
> Is it a child of another object where the numbers would reset, or is it
unique throughout the DB?  If so, why isn’t it the primary key?>
> > On May 23, 2018, at 4:52 PM, Tony Giaccone <> wrote:>
> > >
> > Imagine I have a field in a persistent object, the field is not the
> > key, and I want it to be unique.  So the obvious choice to me is to use
> > sequence value from the db, so that I can avoid trying to calculate a
> > in java.>
> > >
> > Is there an easy way to access that sequence value, from java, using>
> > Cayenne?>
> > >
> > >
> > Tony>

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