One last question, guys. What if there is overlapping between the child tables, so that one instance has more than one "Type"?
Craig L Russell wrote: > > This is a very common pattern in object-relational mapping. The column > that contains the type of crane is commonly referred to as a > discriminator column, and is commonly a CHAR, VARCHAR, or NUMERIC > type. The value of the discriminator column that identifies which > table to look for is referred to as a discriminator value. > > The alternative is to include all possible tables in a query, which is > performance-limiting. > > Craig Russell > Architect, Sun Java Enterprise System http://java.sun.com/products/jdo > 408 276-5638 mailto:[EMAIL PROTECTED] > P.S. A good JDO? O, Gasp! > > -- View this message in context: http://www.nabble.com/Determine-which-child-table-a-record-belongs-to-tp15164998p15166419.html Sent from the Apache Derby Users mailing list archive at Nabble.com.
