Hi

Have just subscribed to your Dia-mail list, but am having trouble finding
ou thow to post a help request on Dial mailing list.

Grateful if you can insert the following post for me, or advise.  Thanks

"Have not designed a db since days of Access2, so very rusty. Am now
considering using 'Base' in LO/HSQLDBv2.  Am a newbie to both UML, Dia, and
Base/HSQL!   I remember with Access, I created my tables, and THEN created
an ERD diagram automatically from the design.    I guess logically the ERD
should come first, and the table creation and links flow from that.  So as
OOo/LO dont appear to be able to Create a ERD, and I saw a reference in OOo
documentation recommending Dia, have been trying to use it.    I
successfully used Dia .972 to draw all the Classes I need, but am a bit
unsure HOW to create the correct links.

1)  My Access generated ERD's had only 1 type of link: lines between table
ID's with arrow symbol at FK end, no symbol at PK end.  As I rcall, the
textbooks of the day used the same symbol - often with a 1:n at the FK end.
 Dia-UML has a slection of link symbols.  Should I use the
UML-Generalisation tool, or the UML-Aggregation tool to create the typical
1:n & other relations ?

2)  When dragging a link towards a key in a class ( to make a relation
between 2 classes) I noticed when the 'handle' reached the border of the
Class, the shape turns 'red' - so I assumed it had connected (as per
Dia.Manual 4.2.5).  After creating many more links, I inadvertantly dragged
the 'handle' further into the Class box, and noticed the shape turns
'yellow' - no ref. in Dia.Manual

I would like an explanation of the difference between the 'Red' and
'yellow' signals, and which should I use.

3)  Once the ERD is complete, what current tools are there to a) report on
its correctness, and b) use it to generate the tables and links in
LO/HSQLDB-V2 ?  My platform is Windows7. I saw a quite old guide using
'tedia2SQL' to create SQL statements. However, the tedia2sql site states it
no longer works as the Dia file format has changed.  Also, I think the
guide used linux and it was not clear if tedia2sql worked in a simple
Windows7 platform.

A minor question using Dia is:  In case I later want to Edit the name or
type of a field (used in many Classes) is it safe to save the .dia
uncompressed, then use 'Notepad' to do a global 'Replace' ?

I am also very much a newbie with SQL.  For some very small lookup tables I
would like to use a 'tinyint' as an auto-incrementing id for new entries.
 All examples seem to use 'Int'.  Any reason I can't use tinyint ?

I apologise for asking such basic questions and will be very grateful if
you can help me through this initial phase with using Dia for front-ending
a Database design."
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