Creating a TreeView DataWindow – PB Docs 125

To create a TreeView DataWindow:

1. Select File>New from the menu
   bar and select the DataWindow tab.

2. If there is more than one target in the workspace,
   select the target where you want to create the DataWindow from the
   drop-down list at the bottom of the dialog box.

3. Choose the TreeView presentation style for the DataWindow and
   click OK.

   

4. Select the data source you want to use.

   You are prompted to specify the data.

5. Define the tables and columns you want to use.

   You are prompted to specify the TreeView grouping columns.

   Multiple columns and multiple TreeView levels

   You can specify more than one column, but all columns apply
   to TreeView level one. At this point, you can define only one TreeView
   level. You define additional levels later.

   In the following example, TreeView grouping will be by department,
   as specified by the dept_id column:

   

   If you want to use an expression, you can define it when you
   have completed the wizard. See “Using an expression for
   a column name”.

   The sample DataWindow shown in “Example” uses the department and employee
   tables in the EAS Demo DB database.

6. Specify the column or columns that will be at
   the top level (level 1) of the TreeView DataWindow.

   The sample DataWindow uses the department name as the top
   level. If you want to display both the department ID and department
   name, you specify that both columns are at the top level.

7. If you want the TreeView DataWindow to display
   grid lines, select the Grid Style check box.

   When you select the Grid Style check box, the TreeView DataWindow displays
   grid lines for rows and columns. You can drag the grid lines to resize
   rows and columns.

8. Click Next.

9. Modify the default color and border settings if
   needed, and then click Next.

10. Review the TreeView DataWindow characteristics.

11. Click Finish.

What PowerBuilder does

As a result of your specifications, PowerBuilder generates a
TreeView DataWindow object and creates:

• A TreeView header band with
  controls that include the heading text of the detail band columns

• The first TreeView level band with the TreeView
  level columns you chose in the wizard

• The detail (leaf node) band that includes all the
  column controls except for first-level columns you selected in the
  wizard

• A level 1 trailer band.

• A summary band, and a footer band.

Here is the sample TreeView DataWindow object in the Design view:

If you selected the Grid Style check box, vertical and horizontal
grid lines display:

Here is the sample TreeView DataWindow object in the Preview view:

Using an expression for
a column name

If you want to use an expression for one or more column names
in a TreeView, you can enter it as the TreeView definition on the
General page in the Properties view after you finish using the TreeView
wizard.

What you can do

All of the techniques available in a tabular DataWindow object, such
as moving controls and specifying display formats, are available
for modifying and enhancing TreeView DataWindow objects. See “Adding and deleting TreeView
levels” to read more about
the bands in a TreeView DataWindow object and see how to add features especially
suited for TreeView DataWindow objects, such as additional TreeView levels
or summary statistics.

DataWindow Object is not updatable by default

When you generate a DataWindow object using the TreeView presentation style, PowerBuilder makes
it not updatable by default. If you want to be able to update the
database through the TreeView DataWindow object, you must modify its update
characteristics. For more information, see Chapter 21, “Controlling Updates in DataWindow Objects.”