Field Properties for Primary and Foreign Keys

[Harold via AccessMonster.com]

Do the field properties have to be the same for the primary key and the
foreign key? Does the data type have to be the same? If I have AutoNumber on
one does the other have to be AutoNumber? If I have long Interger on one does
the other have to be the same? If not what should they be? If the Primary key
was set as required should the foreign key be a required field?

Also, If I set the primary key to AutoNumber what should the foreign keys
field be? AutoNumber? Number? Text?

For some reason the relationship thing is very hard to grasp.

Thanks,
Harold

 

[Rick Brandt]

Do the field properties have to be the same for the primary key and
the foreign key?
No

Does the data type have to be the same?

The types need to be "compatible". Not necessarily identical.

If I have AutoNumber on one does the other have to be AutoNumber?

No. In fact that would not be a workable solution anyway.

If I have long Interger on one does the other have to be the same? If not what
should they be?

See second response.

If the Primary key was set as required should the
foreign key be a required field?

That is typical, but depends on your data requirements. If you want to
allow child records that have no parent then you cannot make the foreign
field a required field. If you want to avoid such "orphans" then you would
make the foreign field a required field.

Also, If I set the primary key to AutoNumber what should the foreign
keys field be? AutoNumber? Number? Text?

Usually LongInteger.

 

[Lynn Trapp]

If you set your the Primary Key of the parent table to AutoNumber, then your
foreign key in any child tables should be Long Integer.

--
Lynn Trapp
MS Access MVP
www.ltcomputerdesigns.com
Access Security: www.ltcomputerdesigns.com/Security.htm
Jeff Conrad's Access Junkie List:
http://home.bendbroadband.com/conradsystems/accessjunkie.html

 

[Harold via AccessMonster.com]

If you set your the Primary Key of the parent table to AutoNumber, then your
foreign key in any child tables should be Long Integer.

Do the field properties have to be the same for the primary key and the
foreign key? Does the data type have to be the same? If I have AutoNumber

[quoted text clipped - 12 lines]

Thanks,
Harold

Thank you!

Harold