by definition, a Primary Key is one or more fields.
I usually use an AutoNumber as the Primary Key, and then a Long Integer as the corresponding Foreign Key.
You can define a UNIQUE INDEX on a field or combination of fields too.
Make a Unique Index on multiple fields:
1. go to the Design view of the table
2. make a unique index on the first field
-- click on the field
-- set Indexed in bottom pane to Yes (No Duplicates)
3. open the indexes window (lightening bolt icon on the Design ribbon)
4. in the second column, the field column, add a second field to the same index by filling out the next row. The first column of the next row will be blank
5. if necessary, add a third field the same way
If you want some of the fields in the index to be allowed to not be filled out then set Ignore Nulls to Yes (in addition to Unique is Yes) in the properties in the Indexes window
~ have an awesome day ~
Is it possible when defining multiple primary keys for a table, to specify that only the combined primary keys can not have duplicates , but the individual key can have duplicate entries?
Posted by: crystal 8 <email@example.com>
|Reply via web post||•||Reply to sender||•||Reply to group||•||Start a New Topic||•||Messages in this topic (13)|