>>>
>>>BTW If the NULL values are NOT needed at all I prefer to set default value to empty field (depends of its type). Only type that allow NULLs is datetime :-)
>>>Of course this is dependong the application, sometimes NULLs are mandatory.
>>
>>Borislav, I came across an issue with the NULLs and may have to adapt the same approach you have - setting default value instead of NULL. If you don't mind, I would like to ask you how you hide the record/row in the parent table with the empty/default field from the user? TIA.
>
>You can't have more than one record in Parent table with DEFAULT value. Otherwise a PK constrain will raise an error.
>How to hide it: Just use WHERE in your SELECT statement.
>
>But I'm still wondering why you need child records w/o parent ones?

Maybe I didn't explain myself right. I want the child table FK to have an option of empty string. In order to do it and maintain RI the parent table must have a row with an empty string value in the field. And of course I don't want the user to change the value in this Parent table for row intentionally or by accident. So I will need to have this row but not to allow user to make a change (therefore) to hid it. One way I though it to have a column/field that identifies this record (e.g. REC_ID) but was hoping for a less-maintenance type approach.