Running Total

rbuser

Hi,

It seems simple enough if I want to do a total of a database field in
RBuilder. I use the DBCalc field and it works like a dream. However, In
Crystal, I could do totals for other fields.

Example: Im using a Variable field to accumulate total. Can I not then just
do a Sum of that Variable? It seems a very tedious way of doing it, unless
im attempting it the wrong way?


Sample:

RepCode (GroupHeaderBand)
Analysis Code (GroupHeaderBand)
Category Code (GroupHeaderBand)
DETAILS variable1 (variable1 = qty * width)
Category Code (GroupFooter) SHOW Total of variable1
(CategoryTotal)
Analysis Code (GroupFooter) SHOW Total of variable1 (AnalysisTotal)
RepCode (GroupFooter) SHOW Total of variable1 (RepsTotal)



There could be n Reps, and n Analysis and n Categories....the totals have
also to be set to zero on any group changes...


Thanks in advance...

nicocizik

Hi Tarun,

I would recommend creating two TppVariable components. Place one in your
detail band and in its OnCalc event update the value of the other
TppVariable with the calculated sum you want to display. Then you can use
the Timing dialog (from the variable's popup menu) to determine when you
would like it to reset its value. See the following article on making
calculations in ReportBuilder.

----------------------------------------------------------------------
TECH TIP: Performing Calculations
----------------------------------------------------------------------

Calculations can be done either on the data access side
or within ReportBuilder.

When designing reports there are always decisions to be made as to
how much processing to do on the data side versus the report side.
Usually doing more on one side can greatly simplify the other. So it is
often a personal choice based on the power and flexibility of the data
and report tools being used.


DataAccess
----------

a. Use SQL - using SQL you can perform many common calculations:

example: Select FirstName + ' ' + LastName As FullName,
Quantity * Price AS Cost,


b. Delphi TDataSets enable you to create a calculated TField object
and use the DataSet.OnCalcFields event

c. Perform any amount of data processing, summarizing, massaging
etc. to build a result set (query or temp table) to feed to the report.


ReportBuilder
-------------

Calculations in ReportBuilder are performed primarily using
the TppVariable component.

a. Set the Variable.DataType

b. Code the calculations using the Variable.OnCalc event.

c. Use the Timing dialog to control the timing of the OnCalc event.
To access the Timing dialog, right click over the Variable
component and select the Timing... option from the speed menu.

d. Set the LookAhead property to True, when you need to display
summary calculations in the title, header, group header, etc.

e. To perform calculations based on the results of other
calculations use the Calc Order dialog of the band. To access
the Calc Order dialog, right click over the Band component
and select the Calc Order... option from the speed menu.


By using TppVariable components ReportBuilder will take care of caching
intermediate results of accumlated calcs that cross pages.

There are a number of calculation examples in the main demos.dpr
project.

---

Additional Notes:

1. Do NOT use Band.BeforePrint or Band.AfterPrint. These events fire
multiple times and therefore should not be used for calculations.

2. Do NOT store results in variables that exist outside of the reports.
For example - form level variables.


--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Hi Tarun,

Nico is right, use two TppVariables.

I had the same problem the first time I used ReportBuilder. Also, there are
some functions in Crystal's Running Total field that can't be reproduced
easily in ReportBuilder, like the DISTINCT COUNT of a variable. I found a
way to do this that works well. I also built a Crystal to RB converter that
eased my conversion, so if you have any questions regarding on HOW-TO-DO
some special features, feel free to ask me.

David