Archive for December, 2009
Normally if there is an unlinked table in one of my reports it is there by mistake. However, I have recently been reminded of some of the neat things you can do with unlinked tables, as long as you are careful. The official name for having unlinked tables is a ‘cross join’. The data that is returned from a cross join is known as a Cartesian product, which means every possible combination of records between the two tables. That is why you have to be careful.
So say you have a customer table with 100 customers in it and you use that table to create a report listing just the customer name. Without adding any filters you would get all 100 records in the report. But then you add a second table that doesn’t link directly to the first, something like the master list of products. If this table has 25 products in it then Continue Reading »
Using unlinked tables (cross joins)
Have you ever noticed that some parameters include a small toolbar below the List of Values (LOV) drop down? This toolbar has two scroll arrows on either side of a small drop down list and two buttons with funnels on them. The toolbar doesn’t show up very often so it took me quite a while to figure out where it comes from and what it is supposed to do. So this article is for anyone else out there who is puzzled.
This is a called the batch interface. It is included in Crystal versions 11 and 12 and appears automatically whenever there are more than 200 values in the parameter list (LOV). To make the long list easier to navigate Crystal automatically batches the values into Continue Reading »
Using the parameter “batch” interface toolbar
If you need to pull a single character out of a character string, or a single item out of an array, you can use a subscript to identify the position you want like this:
{Customer.Customer Name} [3]
This example starts counting from the left to identify the third character or element. Over the years I have had people tell me you could use a negative number Continue Reading »
Using negative subscripts
Check on Ebay, where I regularly find older versions for sale. Just make sure you know what you are purchasing. In 2002 I wrote an article about what to look for when buying CR on Ebay. That article still applies, although some of the product codes listed might be different in newer versions.