Re: Relation-valued attributes (again)

> Given the following table-valued operator:
> Op(AID : Integer) : table { Data : String };
> and the table: T {ID : Integer };
> ... cannot formulate a query (without using RVAs)...

Are you trying to query for operators related to various tables? Below script models it using a small experimental db.

// Create items in directory
(CREATE *table.item ~in = dir)
(CREATE *table1.cls = table)
(CREATE *table2.cls = table)
(CREATE *table3.cls = table)

// Create operators add and subtract.
(CREATE *operator.item ~in = dir)
(CREATE *add.cls = operator)
(CREATE *sub.cls = operator)

// Relate add to table1.
(CREATE table1.operator = add)

// Relate add and subtract to table2.
(CREATE table2.operator = add)
(CREATE table2.operator = sub)

// Relate subtract to table3.
(CREATE table3.operator = sub)

// Find tables related to subtract.
// Finds table2 and table3.
(SELECT %.cls=table & %.operator=sub)
Received on Mon Jan 24 2005 - 20:36:01 CET