How to SQL intersect using Toplink expressions

Question

I try to do this SQL intersect
SELECT part_k FROM ATTR_VALUE
where commodity_n ='dab badge' and attribute_n='Badge Width' and attribute_value_x='10'
INTERSECT
SELECT part_k FROM ATTR_VALUE
where commodity_n='dab badge' and attribute_n='Brand Logo' and attribute_value_x='Jaguar'
using the following Toplink expressions:
Expression e1 = builder.get("commodity").equal("dab badge")
.and(builder.get("attribute").equal("Badge Width"))
.and(builder.get("value").equal("10"));
Expression e2 = builder.get("commodity").equal("dab badge")
.and(builder.get("attribute").equal("Brand Logo"))
     .and(builder.get("value").equal("Jagua"));
Expression myExpression = e1.and(e2);
However, this would not give me the correct result.
Any suggestions would be greatly appreicated.

Answer 1

Right, TopLink doesn't have an Intersect operator. If it did, you might still get the same problem unless you are using a report query to return only the "part_k" value instead of an object since attribute_n cannot have a value of both 'Badge Width' and 'Brand Logo' at the same time.
You can get the part_k values or the objects from the ATTR_VALUE
table by using a report query for the second expression as a subquery to the IN clause. Something like
  ReportQuery subquery = new ReportQuery(yourclass.class);
  ExpressionBuilder subBuilder = subquery.getBuilder();
  Expression e2 = subBuilder.get("commodity").equal("dab badge").and(subBuilder.get("attribute").equal("Brand Logo")).and(subBuilder.get("value").equal("Jagua"));
  subquery.setSelectionCriteria(e2);
  subquery.addAttribute("partk");
  Expression myExpression = e1.and( builder.get("partk").in(subquery) );Regards,
Chris