Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
{
	    	String exprText = ((IScriptExpression) expr).getText();
	    	CompiledExpression handle = compiler.compile( exprText, reg, cx);
	    	expr.setHandle( handle );
	    }
	    else if ( expr instanceof IConditionalExpression )
	    {
	    	
	    	
	    	IConditionalExpression ce = (IConditionalExpression) expr;
	    	ce = transformConditionalExpression( ce );
			
	    	prepareExpression( ce.getExpression(), groupLevel, cx, reg );
	    	if ( ce.getOperand1() != null )
		    	prepareExpression( ce.getOperand1(), groupLevel, cx, reg );
	    	if ( ce.getOperand2() != null )
		    	prepareExpression( ce.getOperand2(), groupLevel, cx, reg );
	    	 
	    	
	    	expr.setHandle( ce );
	    }
	    else
	    {
	    	
	    	assert false;
	    }
	}
	/**
	 * When a TopN/TopPercent/BottomN/BottomPercent ConditionalExpression is
	 * set, transform it to