Crystal Reports 10 Enforce Join

[Trixie2004]

Hi,

What is this new feature? I've read through online help and it's cryptic. I've searched the BO website and not found anything different than what it has in the online help... I've also tried using it and had no change in results returned. Am I missing something? Does this actually do anything, and if so, what?

Thanks for any input.

 

[jdemmi]

This is used when you are joining tables but only selecting from 1. (Your join is used to constrain the result set, but not actually a part of the result set or not used to obtain\create the result set).

The "not enforced option" will allow CR to "use" the join ONLY if it is required by the select statement.

USE THESE TABLES for the example below.

ORDERS(order_number, customer_ID, total)

CUSTOMER(customer_ID, customer_name, address)

LINK ORDERS.CUSTOMER_ID to CUSTOMER.CUSTOMER_ID

 

[Trixie2004]

Thanks for your response!

OK, so then why would you want to use it?

 

[jdemmi]

Many cases....one is the example I described. I need the join ONLY if the user makes certain parameter selections.

This was a VERY basic example and this function can be used to do much more robust things.

 

[Trixie2004]

So great, I can see in the example where it passes it into the SELECT statement, but why is this important? Why does it matter? Will t make the report more efficient or something? Also, what kinds of robust things are you talking about, because I still can't figure out a reason why this option is important to use and change from the default (Not Enforced). Thanks for any insight.

 

[Trainingjason]

I am currently learning this feature, my understanding is that enforcing is similar to a query in Access. In previous versions of crystal if you only selected one field from a table, whilst there were many other links. Then crystal would only return the values from the original table. In contrast in access, a large table in essence behind the scenes is created but only that one field is used.

From my perspective if a table is not called or not passed through by a field then its records are not seen or used. Where as enforcing means that it treats the result as a query and shows all the data.