Summary Statistics

Relational databases provide tools that allow reports, forms etc. to display summary information such as a sales report detailing at the bottom the total value of sales listed on the report.

In effect, we are talking here about calculations.

In Filemaker Pro reports, these calculations are created as new fields fields with the type being either calculation or summary. Where these fields are placed in the layout of a report will affect the value of the calculation displayed. A field in a sub-summary part will in all likelihood produce a very different result to the same value placed in the body or header of a report.

As a general rule, try to always use summary fields when counting or totalling field values.Due to the nature of a particular database this may not always be possible. However, summary fields have advantages in that they will be calculated in the table in which a report is created, they are very simple to create due to the restricted nature of them and the values that they return are flexible, with a summary field value displayed in the body differetn to one displayed in a sub-summary. They will also accurately reflect values based on any search-criteria that a user supplies.

On occassion, a summary field cannot be used (such as trying to add a field that is in another table - no instantly possible). In this circumstance, ask whether a calculation field will meet the purpose you are trying to achieve.

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