Crystal Reports - Basic Formula Generations

1) Comparing against a fixed quantity (e.g. 100)
-Choose Report->Select Expert
-Select the column that you are going to compare from the table
-Choose "is less than or equal to" from pull-down list and enter 100 in the comparison field.

2)Comparing against a quantity the varies
-Choose Report->Selection Formulas-> Record
-Write the formula into Formula-Field as;
ex: {Table.Column}+{Table.Column}={Table.Column}

3)Comparing against a quantity that initiated in the runtime.
-In the Field Explorer tree, right-click the Parameter Fileds option and choose "New" command.
-Enter name for the parameter field, some prompting text, and the user is tom make.
-Click the Select Expert
-Select the field you want to compare
-In the pull down list select "is greater than or equal to"
-Pull down the list and Select {?ParameterFieldName}