One of the DataWindow object presentation styles, Group, is a shortcut to creating a grouped DataWindow object. It generates a tabular DataWindow object that has one group level and some other grouping properties defined. You can then further customize the DataWindow object.
You specify columns on which to group a DataWindow in the Set Report Definition page of the Group DataWindow wizard, or in the Specify Group Columns dialog box that you open from the DataWindow painter.
Figure 22-6 shows selections for grouping by department, as specified by the dept_id column.
Figure 22-6: Selecting a column on which to group a report
Figure 22-7 is an example of a Group style DataWindow object in the Design view of the DataWindow painter.
Figure 22-7: Design view of a DataWindow with a Group presentation style
To create a basic grouped DataWindow object using
the Group presentation style:
Select File>New from the menu bar.
The New dialog box displays.
Choose the DataWindow tab page and the Group presentation style, and click OK.
Choose a data source and define the data.
You are prompted to define the grouping column(s).
Drag the column(s) you want to group from the Source Data box to the Columns box.
Multiple columns and multiple group levels
You can specify more than one column, but all columns apply
to group level one. You can define one group level at this point,
and define additional group levels later.
If you want to use an expression
If you want to use an expression, you can enter it as the
Group Definition on the General page in the Properties view after
you have finished using the Group Wizard. You can specify more than
one grouping item expression for a group. A break occurs whenever
the value concatenated from each column/expression changes.
Click Next.
PocketBuilder suggests a header based on your data source. For example, if your data comes from the Employee table, PocketBuilder uses the name Employee in the suggested header.
Specify the Page Header text, specify page break and page numbering properties for data groups, and click Next.
If you want a page break each time a grouping value changes, select the New Page On Group Break box.
If you want page numbering to restart at 1 each time a grouping value changes, select the Reset Page Number On Group Break box and the New Page On Group Break box.
Select Color and Border settings and click Next.
Review your specification and click Finish.
The DataWindow object displays with the basic grouping properties set.
As a result of your specifications, PocketBuilder generates a tabular DataWindow object and:
Creates group header and trailer bands
Places the column you chose as the grouping column in the group header band
Sorts the rows by the grouping column
Places the page header and the date (as a computed field) in the header band
Places the page number and page count (as computed fields) in the footer band
Creates sum computed fields for all numeric columns (the fields are placed in the group trailer and summary bands)
You can use any of the techniques available in a tabular DataWindow object to modify and enhance the grouped DataWindow object, such as moving controls, specifying display formats, and so on.
For information about the bands in a grouped DataWindow object and how to add features especially suited for grouped DataWindow objects (such as adding a second group level, defining additional summary statistics, and so on), see “Defining groups in an existing DataWindow object”.
DataWindow object is not updatable by default
When you generate a DataWindow object using the Group presentation
style, PocketBuilder makes it not updatable by default. If you want
to be able to update the database through the grouped DataWindow
object, you must modify its update characteristics. For more information,
see Chapter 20, “Controlling Updates in DataWindow Objects.”
