Nested Query Scopes

You can nest scopes by using nested SELECT statements. Names in an inner scope hide identical names in an outer scope.

In the query below, the inner SELECT creates a new scope, the positions of the current portfolio, inside the outer SELECT ’s scope, /portfolios. This inner scope (the collection of entry values from the /portfolios region) is first searched for the secId element. The outer scope is searched only if the secId element is not found in the inner scope.

IMPORT javaobject.Position;
SELECT DISTINCT * FROM /portfolios
   WHERE NOT
    (SELECT DISTINCT * FROM positions.values TYPE Position
       WHERE secId='YYY').isEmpty

This statement shows the outer scope in bold. The outer scope has all the attributes of a Portfolio in it.

IMPORT javaobject.Position;
SELECT DISTINCT * FROM /portfolios
      WHERE NOT
        (SELECT DISTINCT * FROM positions.values TYPE Position
            WHERE secId='YYY').isEmpty

Now the statement with the inner scope is shown in bold. The inner scope has all the attributes of a Portfolio in it (inherited from the outer scope), and all the attributes of a Position as well.

IMPORT javaobject.Position;
SELECT DISTINCT * FROM /portfolios
   WHERE NOT
     (SELECT DISTINCT * FROM positions.values TYPE Position
         WHERE secId='YYY).isEmpty