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Hi John,

John R. Sowden schrieb:
Why do the Libreoffice powers that be define dbase/xbase as  a flat file
database, not a relational database.  The below definitions from the
Base Intro documentation demonstrate what I am saying:

Do you have a direct link?


*Flat databases*

A flat database contains one or more tables, each containing one or more
fields. Each table is completely independent of all the other tables in
the database. For example, I have an address database with seven tables
in it. One has my family's contacts, another has my business contacts,
and another has my wife's family contacts. While some contacts are
contained in more than one table, different tables may not have the same
information about the same person.

dBase is a flat database program. LibreOffice and several database
programs can also create flat databases.

*Relational databases*

Relational databases contain one or more tables with one or more
relationships; each relaltionship is defined by a pair of fields. One
field of each pair belongs to one table and the second field belongs to
the same or a different table. Where relationships exist between fields
in the same or different tables, a flat database could still be used,
but it provides no mechanism for defining the relationship. Instead the
same data must be entered in both fields, making data entry errors more
likely. A well designed relational database requires the data to be
entered only once, reducing possible errors.

I think, it is a wrong definition of the term 'relational database'. The word 'relation' in 'relational database' means the mathematical definition of 'relation', which is connected to 'tupel', a organization of data in rows and columns. It is not about a 'relationship'.

Another database model is a hierarchical model for example, which is tree-like.

http://en.wikipedia.org/wiki/Relational_database.
http://en.wikipedia.org/wiki/Database_model
http://de.wikipedia.org/wiki/Datenbankmodell

It seems, that 'Flat database' is used for a database with one single table. But such a database would still be a relational database. My German text book does not have any term which would correspond to 'Flat database'. And the German Wikipedia article has no database model 'Flat database'.


dbase is a relational database per the above definition.  I link 2
tables with 1 field so I can refer to data in the second database so
data does not have to bbe entered multiple times.  In our alarm
monitoring station, when a police dept. changes its phone number, we
change 1 field in 1 database.  Hundreds of subscriber records refer to
that field to populate the data screen.  It seems that LO ptb either
have a problem with dbase/xbase, or they are (were) uninformed of the
facts.

dBase is a relational database application because the data is organized in tables.

I think, there is no need to introduce the term 'flat database' at all. The distinction is in the management system. For files in dBase-format and for spreadsheets, LibreOffice itself is the database management system. For all other database connections, it uses an external database management system.

Kind regards
Regina


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