Re: [libreoffice-users] Adding fields to existing Base table

   If you are going to create a database, you plan it THOROUGHLY! Beginning with a small simple 
database and expanding it to a very large one is only asking for a complete disaster! Unless you 
are using a flat database, your tables need to be in at least fourth normal form. Repeatedly adding 
additional fields can cause the table containing these fields to loose its normal form. Then there 
is no way to know if your quieries and reports contain acurate information or not.
   The purpose of a relational darabase is to enter data without any repetition of it. 
http://wiki.documentation.org/Documentation/Publications has chapter two of the Base Guide on it: 
Planning/Designing your Database. Use it to plan what you need. Only then select the database 
engine you will use to create the database. Your database is only as good as your plan!




-------- Original message --------
From: Girvin Herr <girvin.herr@sbcglobal.net> 
Date:07/10/2014  4:17 PM  (GMT-05:00) 
To: users@global.libreoffice.org 
Subject: Re: [libreoffice-users] Adding fields to existing Base table 

Dave,
I use the MySQL server and have added table fields before.  It is simple 
in the LO Base table design window.
Tables -> right click on table -> select Edit
MySQL accepts these changes and adds the field.  Of course, then you 
must add the new field toyour forms, queries, relationships and 
reports, as needed.

Deleting fields is another matter.  I have had problems with MySQL field 
deletions before - especially messing with the primary key. Then it may 
be a matter of directly using the MySQL interface program, with some SQL 
code, bypassing LO Base.  But it is possible.  So be careful what you 
do.  Think it out first.

I have no experience with the internal HSQLDB server.  From what I read 
on this forum, using the internal HSQLDB server with a large 3GB 
database is not recommended.  Best to use MySQL, MariaDB, or Postgresql 
for such large databases.  Also, remember that there may be no way to 
easily port your data from the internal HSQLDB database to an external 
database if you so decide to make the change in the future.  You may end 
up re-entering it all.  Best to make the commitment now, before you run 
into a wall.  Note that I consider my databases "large" at 2.7_M_B for 
the current largest.  IMHO, 3GB is out there.

HTH.
Girvin Herr


On 07/10/2014 12:27 PM, dave boland wrote:
> I'm setting up a database that is small (three tables, may grow to 3GB
> over next year).  I need a strategy to deal with the unknown, which is
> how to add fields to an existing table.  I read in the docs that doing
> this can be painful and it is required to put something in each field
> for each record.  Do I have this correct?  If so, how do I handle the
> inevitable "...would you add..." that is sure to come within the next
> few months?  I would add them now, but I really can't anticipate how
> many fields will be added or their requirements.
>
> In general, do other databases have similar restrictions?  At some time,
> when I have time, I will consider MySQL, MariaDB, and others.
>
> Thanks,
> Dave


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