Yes, you were not at all using the INSERTED/DELETED tables in your trigger. In your case INSERTED table is the one available during inserts. So your trigger could be something like this.
ALTER TRIGGER [tr_wba_01]
SET wba.wbaprda = convert(varchar(10), getdate(), 105)
FROM wba, INSERTED
WHERE wba.column_name = INSERTED.column_name
-- Column_Name could be the primarykey or something unique that identifies the row.
The question here is ... Is wba.wbaprda not a DATETIME type?
Why don't you set DEFAULT value of that column as Getdate() than writing a trigger?
- Vijay G
Strive for Perfection