Table constraint

[Chunk]

In Oracle, you can set up table constraints which constrain data accross mutliple attributes/fields. Can you do this in Access?

For example. I have:

OrderLine(orderNum,orderLineNum,[productNum],date)

I dont want to allow for the same product to be put on one order twice. Therefore, (orderNum,productNum) must be unique, but productNum is not a part of the primary key so it can be repeated in every row for all the database cares.

How can I set this up.

In Oracle I would do something like:

CONSTRAINT chk_prod CHECK UNIQUE (orderNum, productNum)

Thanks for any help.

 

[RV]

Access doesn't come with table constraints.
You would need to define a Before Update event on your form, using the DCount function.

RV

 

[RoyVidar]

In Access you'd probably open the table in design view, find the index button (to the right of the primary key button on the toolbar), enter a name for the new index, select the fields, and in the bottom part of the box, set the properties of the compound index.