Constant selection in Crystal Reports (like BEx)

Question

Hello! I'am sorry if this question have printed answer already but I can't found it.
I have BEx report like this:
          month1                   month2                         monthN
items     amount                   amount                         amount
item5     100                      50                             50
item8     200                      150                            100
item9     150                      20                             200
and I have hierarchy on infoobject "items" too, for example:
item1
    item2
         item5
    item8
item3
    item9
I created hierarchy group in Crystal Reports and got the report like this:
                          month1                   month2                         monthN
items                     amount                   amount                         amount
item1                     300                      200                            150
    item2                 100                      50                             50
         item5            100                      50                             50
    item8                 200                      150                            100
item3                     150                      20                             200
    item9                 150                      20                             200
But I need in calculate one more key figure - item amount percentage of item1 amount ({amount of current item}*100/{amount of item1}). Item1 have amount = 300 in my example, so I need report like this:
                          month1                   month2                   monthN
items                     amount perc              amount  perc             amount perc
item1                     300    100%              200     100%             150    100%
    item2                 100    33%               50      25%              50     33%
         item5            100    33%               50      25%              50     33%
    item8                 200    66%               150     50%              100    66%
item3                     150    50%               20      7%               200    133%
    item9                 150    50%               20      7%               200    133%
In BEx I used KF amount with restriction items="item1" and option "constant seklection" but I can't find instruction, how-to or example - how I can design it in crystal reports???
Please help me - I think you know it as it's common report users wish.

Answer 1

There really isn't anything like a conditional SUM (like SUMIF in Excel), but you can sum an IF statement, kinda like this...
SUM (IF {Amount} > 100 THEN {Amount} ELSE 0)
As far as the sub-report idea... Yea that should work.
1) You can pass a value from a sub-report back to the main report by using a shared variable. {Look up "Shared variables" in the online help for more info}
2) Yes. The sub-report will refresh with the main report.
3) Yes. Formula results from the main report can be passed to the parameters of the sub-report. This will also automatically hide the sub-report parameters from the user.
3a) From the main report, right click the sub-report and choose "Change subreport links..."
- Find the field or formula in the "Available Field:" window and click it over to the "Field(s) to link to:" window.
- Find the corresponding sub-report parameter in the "Subreport parameter field to use:" area.
Not too tough actually.
HTH,
Jason