Microsoft Access 2010 : Enhancing Reports with VBA - INTRODUCTION TO REPORTS

1. How Reports Are Structured

Several different components make up a report. Perhaps the most important are the various sections and group levels that are defined in a report.

Sections are used to display data and other controls such as labels or combo boxes. The following table describes the types of sections in order.

One thing that sets reports apart from forms is the capability to group data. Grouping enables you to create aggregates or to view related data in a hierarchical fashion using group levels. Let's say you are tracking sessions for a conference and the attendees for each session. Using a report, you can group by the session as well as the time of the session, and display the attendees for each session.

Reports also support sort levels in the hierarchical data. A sort level is the same as a group level, but without a header or footer section. Data within a group or across the report is sorted by the specified field. You can create a maximum of ten group and sort levels in a report. These levels are stored in GroupLevel objects in the GroupLevel property of the report.

You can add a subreport to a report. A subreport can show related data in a hierarchy, or you can use subreports to build dashboard-style reports.

2. New in Access 2007

Before we take a look at some of the new features related to reports in Access 2010, let's take a look at some of the features that were changed for reports in Access 2007.

Reports were among the most improved areas in Access 2007. Several new features have been added to make reports both easier to create and more powerful. For starters, Layout view allows you to design reports while you are viewing your actual data. Many of the tasks of creating a report, such as formatting, sorting and grouping, and adding totals are handled in Layout view while your data is onscreen. As a result, you can accomplish many design tasks without having to switch between Design view and Print Preview. Later on, we'll take a quick look at improvements that were made to Layout view in Access 2010.

A report opened in Print Preview is really just an image, so you cannot easily search for data or sort or filter content. Access 2007 introduced Report view, which provides a new view of the data in a report that rivals that of forms.

Sorting and grouping is another area that has been enhanced in Access 2007. The sorting and grouping dialog box used in previous versions of Access has been replaced with the new Group, Sort, and Total pane, which enables you to quickly create group levels and sort levels.

Creating reports has also been made easier using the Layout view feature. Layouts are groups of aligned controls that resize and move in conjunction with one another. Layouts have been greatly improved in Access 2010, so we'll take a closer look at Layout view in the next section.

Layouts also enable you to add gridlines that grow or shrink with the data. These are much easier than creating lines in previous versions of Access. The Line and Rectangle controls are still available if you require more control over the placement of lines. Figure 1 shows a report with a tabular layout that has gridlines.

Figure 1.

3. New in Access 2010

Access 2010 adds some additional improvements to features that were added for reports in Access 2007. Let's take a look.

3.1. Enhancements to Layout View

Layout view was first introduced in Access 2007, and creates a more WYSIWIG approach to designing forms and reports. Originally, there were two types of layouts you could create: stacked and tabular. Access 2010 greatly improves the experience of designing objects in Layout view by removing previous limitations.

These new improvements are things such as:

• Adding controls in Layout view: Previously you could only add text boxes and image controls in Layout view.

• Merging and splitting cells: Controls can span multiple rows or columns.

• More control over the placement of controls: You can drop a control virtually anywhere within a layout.

• Easier to insert and delete rows and columns: New menu commands have been added to simplify these tasks.

• Support for new Office themes: You can use themes to apply a consistent style to both forms and reports.

3.2. Web Reports

Much of what is new in Access 2010 can be used to build applications for Access Services, and reports are no exception. Reports in an Access Services application enable you to create a report, publish it to an Access Services site, and send the URL of the report to end users for viewing. This is powerful, but there are a couple of things you should be aware of.

First and foremost, unlike forms, reports do not support events or macros for custom logic in the report. This means there is no programmability for reports in Access Services. When you create a web report in Access 2010, no events will be listed in the property sheet for the report or controls on the report for this reason.

Second, reports only support a few types of controls. The supported controls are text box, check box, label, and hyperlink. Combo boxes and list boxes are not supported, which means that if you want to use a lookup field to display data on a report, you will need to modify the query to include the lookup table to display values on the report.

3.3. SubReports in Forms

For quite some time, we've been able to view subforms in reports, but not the other way around. Reports have never been able to be viewed as a subform on a form — that is, until now. Using Access 2010, you can set the SourceObject property of a subform control on a form to the name of a report. This was largely done to enhance the new navigation control in Access 2010, but you can use your own reports in subform controls without a navigation control as well.

You can also add reports to a subform control in an Access Services application.

3.4. Detecting Whether a SubReport Is Opened in a Form or Report

Once you've started to use subreports in your subforms, it might be necessary to determine whether a report is open in a subform. To determine this, the Subform object in the object model now includes a Report property. The following code shows how to determine whether a report is open in a subform control.

Private Function IsSubreport(objSubform As SubForm) As Boolean
    On Error Resume Next
    IsSubreport = (Not objSubform.Report Is Nothing) And (Err = 0)
    On Error GoTo 0
End Function
                                                      

Now that reports can be hosted in a subform control in Access 2010, it may also be necessary to determine whether the object in the subform control is actually a subform. The following code shows how to do this:

Private Function IsSubform(objSubform As SubForm) As Boolean
    On Error Resume Next
    IsSubform = (Not objSubform.Form Is Nothing) And (Err = 0)
    On Error GoTo 0
End Function
                                                      

Both of these functions work by testing the object inside the subform control. In the case of a subreport, we're testing the new Report property of the Subform object. In the case of a subform, we're testing the Form property. Also notice that both functions include inline error handling. This is because Access throws a runtime error if the Form or Report properties of the Subform object are invalid.

The following sample code shows how to use these functions:

Private Sub cmdTest_Click()
    If (IsSubform(Me.NavigationSubform)) Then
        MsgBox "The name of the subform is: " & Me.NavigationSubform.Form.Name
    Else
        MsgBox "The specified subform control does not contain a subform."
    End If

    If (IsSubreport(Me.NavigationSubform)) Then
        MsgBox "The name of the subreport is: " & Me.NavigationSubform.Report.Name
    Else
        MsgBox "The specified subform control does not contain a subreport."
    End If
End Sub
                                                      


					  

3.5. Improved Conditional Formatting

Conditional formatting for controls in Access 2007 and previous versions allowed up to three defined conditions and the default condition. With conditional formatting in Access 2010, you can now have up to fifty conditions defined for a text box or combo box.

Having the opportunity to add more conditions may eliminate the need for complex logic in code. This is a big win, but it doesn't stop there. In addition to being able to add more than three conditions, there are also new options available for conditional formatting in Access 2010.

If you've used conditional formatting in Excel 2007 or Excel 2010, you may be familiar with data bars. Data bars are a way to apply formatting to a control based on the entire data set. For example, let's say that you have a report that shows number of sales for the month. You could apply data bar formatting to show the person with the highest figures. This type of visualization can make reports easy to understand and very interesting. Figure 2 shows data bars on a report in Access 2010. The first data bar includes the text in the control, and the second omits the text and only displays the data bar.

Figure 2.