Why Setup Relationships between tables?

  • Thread starter Thread starter BC
  • Start date Start date
B

BC

I'm new at Access programming and I don't quite understand what one
gains by setting up relationships between tables.
Comments requested please?
 
Hi

First of all, setting up relationships is one of the many common steps
involved in designing a relational database system. Let's back up a little
and throw in another step that's just as common in designing a relational
database system, and that is Normalizing tables. Normalizing tables is
essentially the process of breaking up a whole slew of related information
into more efficient, distinct, manageable, units. Once we achieve
normalization, since our "slew of information" is now broken up into units
we need to define how the distinct units are related to one another so that
the database management system (i.e. Access) can reproduce this "slew of
information" intact.

So, why setup relationships between tables? Because the tables had been
normalized. The less normalized your tables are, the less you need to setup
relationships. As a matter of fact, just about all database application can
be done with one table. That's right! With one huuuuge table, I guarantee in
this case that you dont ever need to setup relationship <g>.

To answer your question though (what do we gain by setting up
relationships).
Well, we dont gain anything from setting up relationships, at least not
directly. We do, however, reap the benefits of data integrity, efficiency,
reliability from normalization of tables which, in turn, requires
relationships to be setup.


HTH
Immanuel Sibero
 
I thank you!

Would you happen to know why when I broke up a table into three tables
using the Tools/Analyze/Table wizard that whrn I afterwards opened one
of the tables I get a + sign on each of the records. When I clicked on
the + sign I could see the data from the other table; but when I checked
"Realationships", it did not show any relationships?
 
but when I checked
"Realationships", it did not show any relationships?
Click to expand...

The relationships window has always been flakey, to say the least. It
frequently fails to show relationships that are definitely there. The first
thing to do is right-click in the window and choose "Show All", which may
bring it to light.

There are VBA methods for enumerating relationships, but they are not
pretty.
 
Tim,

If it were not for good newsgroups, I don't think I would be able to
develop any code that did more than display a table!
THANKS A BUNCH!

"Show All", which may BROUGHT IT TO LIGHT!

You would think that would be the default setting! DAAAAAAAAH!
 
You would think that would be the default setting! DAAAAAAAAH!
Click to expand...

Not if you have twenty or thirty tables you wouldn't... nevertheless I
strongly suspect that this is not "working as designed"


All the best


Tim F
 
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