Changing Chart Labels, Titles and Data Display with Formulas

Use the Property Sheet (Actions group) to change chart values and titles.


The chart title is usually a simple text string.  Labels and values sometimes may contain more complex formulas.  For example, you may show a name (text) instead of an ID value:


Only fields included in the database query are available for use.  By default, if you selected a primary key field as an index field in the Charting Wizard’s Options step, all non-binary and non-large text fields will be included in the query and are available for use.  However, if the index field is not a primary key, only the index field will be included.

You can include, change or exclude fields and aggregate functions in the Query Wizard.  Note, that adding fields potentially changes the result set because the SQL query must include a GROUP BY clause for all non-aggregate (those without functions) fields.  Accordingly, the only case when final values will not be affected is when the original index field is unique (a primary key, for example).

Formulas are useful for implementing Display As (display foreign key as) functionality.  For example, to create a chart of total sales per product category, you might want show category as category name, rather than as an ID value.  In this case, select Category / CategoryID as an index and than modify the formula.  Note, that same result set is possible to get if Products and CategoryID are selected, but in this case despite exactly same values for SUM only CategoryID field is included. So it is always a better strategy to select a primary key from the parent table instead of selecting a foreign key field in the child table for the index field.

Data formulas

Similarly you can change the data display formula.  By default, the data formula fetches data from a database query via a LOOKUP() function, but you can select different data if your query contains more than one aggregate function, and you can modify the value with arithmetic operations.  Also if you elected to show values as percentage in the Charting Wizard, the query retrieves values values and calculates percentages.

You can modify the display format of the data values, but make sure that your data’s formula always returns a numeric value.

To verify which query your chart uses, look in the Queries section of the Property Sheet.

Note: when you modify your query, especially when adding or removing fields, you must ensure that any formula using the query is appropriately updated appropriately.

Using chart formulas in code customizations

These formulas are used when populating arrays of labels and values for a chart using one of the following methods:




For example:

Dim indexArray() As String = UnitPriceSumQuery.GetComposedStringColumn("""Employee :"" + LastName + "" "" + FirstName", EvaluateFormulaDelegate, EvaluateFormula("Resource(""Txt:RemainderLabel"")"))

Where the first string is a Formula. These calls are generated automatically but could be overridden in Set…Chart method on a Code tab for a chart.