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New Blog Posts: Merging Reports - Part 1 and Part 2

as to add?

edited September 2002 in General
good morning, I am making an extract report, where I list the balance of the
bill and the values of he/she enters and exit, the problem is that the sum
is duplicating when the report is in visualization way with the user
navigating for him. I am adding in the event Before Print in that way..

I liquidate := (I Liquidate + Value)

where should make this sum type, for not duplicating..

(Excuse me for my English)

Comments

  • edited September 2002
    Use a TppVariable and use its OnCalc event handler.

    Cheers,

    Jim Bennett
    Digital Metaphors

    ------------------------------------------------------------------------
    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.



    --
    Tech Support mailto:support@digital-metaphors.com
    Digital Metaphors http://www.digital-metaphors.com



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