Displaying a Random Sample (number or proportion)

If you need to randomly select and display a given number of records, or a user-specified proportion of the records, here's a simple approach:

Step 1:
Place the following formula (@Random_Number)
in the detail section:
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Rnd()
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Step 2:
Sort the records by @Random_Number (ascending).

Step 3:
In the suppress attribute of the detail section enter the following expression:

3.1 If you need to display a given number of Records:
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RecordNumber > {?Show_N_Records}
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where {?Show_N_Records} is a parameter allowing the user to
specify the number of records to be shown.

3.2 If you need to display a given proportion of Records:
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RecordNumber > ({?Show_X_Percent}/100) * Count({some_field})
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where {?Show_X_Percent} is a parameter allowing the user to
specify a number between 0 and 100.

Cheers,
- Ido

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