[Tutor] question about "hiding" a function/method in a class

Alan G alan.gauld at freenet.co.uk
Sat Jun 4 00:16:02 CEST 2005


> Maybe it's not a "schema" exactly.
>
> |Table Name|Fields  |Type   |Size|Primary Key|Not
Null|Unique|Foreign Key| ...
>
> |'s represent each cell. It's just a way to organize your thoughts,
and have
> something a little more readable than an SQ script for a DB schema.
There's been
> less than 20 tables in a database for most of these applications
that we write.
> It's clear enough to see the relations(there's another column
references).

OK, so its just a tabular version of the SQL statements, I see.
I guess that works for small schenas, I tend to think in terms
of several hundred tables in a schema so I forget not everyone
is doing those kinds of things!

> > You do know that there are lots of ERD programs that allow you to
draw
> > the schema as an ERD and generate the SQL DDL directly? In fact
even
> > Visio


> Can you point me to some Open Source/Free ERD programs that work
with
> Postgres?

I've never used Postgres but I've used several commercial tools that
generate Oracle, SQL Server, Sybase, Informix, DB2, etc. So I suspect
they have postgres DDL drivers too. A couple of tools that spring to
mind are Popkins System Architect and ERWin. Both are commercial but
ERWin can be had for less than a single day of a contractor, and
Popkins for less than a week. For any serious database development
they pay back almost immediately.

I've used Visio too for a smaller system - about 60-70 tables and
it worked OK with Oracle. Again it cost less than a day of a staffer's
time never mind a contractor!

> (I'll google after I send this message.) I'd certainly would like to
> look at ways to do this better.

I don't know of any free tools but I'll be surprised if there aren't
some at least - even if just demos with limited numbers of tables.
The commercial tools are so cheap(relatively) that we've never even
looked for freeware... Many of the UML tools (BOrland, iLogix,
Rational Rose etc) have free trial versions which might be workable,
at least to prove the concept before investing real money...

Alan G.



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