Re: [Squirrel-sql-users] graph plugin edges?

[Robert M. <rob...@gm...>]

On 4/14/10, Dave Howorth <dho...@mr...> wrote:
> > So, if you want to have the graph plugin show relationships
> > visually, you must - for the foreseeable future - define foreign keys
> > using regular SQL in SQuirreL."
>
> I don't understand this bit though. (a) I don't understand why it starts
> with 'so', which implies that it's a logical consequence of the
> preceding text, which it isn't on my understanding. So I have probably
> misunderstood something. (b) I don't understand how I can define foreign
> keys in SQuirreL? The foreign keys are defined in the database schema,
> surely?

Yes indeed, foreign keys are a form of constraint that most database
support.  The wording above could maybe be improved, but it is try to
say that you must create the foreign keys using SQL, such as, "alter
table child_table add constraint constraint_name foreign key
(column_name) references parent_table".

If you have foreign keys defined accordingly, then the JDBC driver
that SQuirreL is using should report them, and likewise the graph
plugin will render lines between tables with said FK constraints.

Rob