apress pro access 2010 development phần 2 pdf

Using the Form Wizard From the Create tab of the ribbon, click the Form Wizard button.. In the first dialog box of the Form Wizard, select the Category table, and then move the Category

Figure 5-23 Collapsing each of the categories

This hierarchy of attributes functions much like the CheckedOut By Month field that you added to the Row area You can collapse or expand specific values to drill down into the data Using this approach, you can add any number of fields to the Column or Row areas

 Tip You added the MediaDescription field to the right of the CategoryDescription field This caused the media type to be a secondary level under category If you had dragged it to the left the CategoryDescription, then the media type would be the top-level in the hierarchy

Creating a Field Hierarchy

When planning these multi-level groupings, you should try to use attributes that are logically related The date field is the perfect example Months and weeks are logical subdivisions of a year as are days, hours and minutes So it is logical to drill down from year to month to day However, categories and media types are orthogonal attributes

When using multiple fields in a Column or Row area you have to specify the order in which the fields are used in the hierarchy In this case the category was first so you can see how a summary for each category and then drill down to see what media type were loaned from each category By placing media type as a sub-group under category, you cannot view a media type across all categories

Someone may prefer to see how a specific media type was represented in each category You cannot accomplish both at the same time When you have a situation like this where you need to summarize in both directions, then you should put one attribute in the Row area and the other in the Column area

A better design would be to move the CheckedOut By Month field to the Filter area and move the MediaDescription field to the Row area Make those adjustments in your PivotTable View and it should look like Figure 5-24

Figure 5-24 Rearranging the fields in the PivotTable View

Notice that you can simultaneously see both category and media type summaries, as well as how the other attribute was represented in the total Click the dropdown button next to the CheckedOut By Month field in the Filter area The dialog box shown in Figure 5-25 will appear which you can use to filter the

view to include only specific months or days, for example

Figure 5-25 Selecting the dates to include

Remember, the Filter field(s) define the set of records that are included in the PivotTable View By

placing the CheckedOut By Month field here, you can control the time period that you want to analyze Date fields are often a good candidate for a Filter field However, if you want to see an attribute tracked

over time, you will generally use the appropriate date field in Row area

In the current database schema, there is a single-level categorization of items For a large library you would probably want multiple levels, such as the Dewey Decimal system The Dewey Decimal system

defines three main levels of organization, which are referred to as classes, divisions, and sections It is

called a decimal system because there are 10 classes that each has 10 divisions, which, in turn, has 10

sections each Thus there are 100 divisions and 1000 sections

If you were to implement a structure such as this, then this would be an excellent candidate for

using a multi-level field hierarchy in your PivotTable View Look for other fields that logically fit into a

hierarchy The Author and Title fields are another good example

Using the PivotChart View

Once you have defined a PivotTable View, you can easily turn this into a graphical presentation Select

the PivotChart View button from the lower right corner or select the PivotChart View link from the View

button in the ribbon The default settings will probably look something like Figure 5-26

Figure 5-26 The initial PivotChart View

Configuring a PivotChart View

This is a fairly complex PivotTable with several values to chart Each value is displayed as a bar in this bar graph To see what each bar represents, you’ll need to display the legend Click the Legend button in the Design tab of the ribbon The legend will look similar to Figure 5-27

Figure 5-27 The PivotChart legend

The problem with this chart is that it is trying to display too many values In a bar chart, the Column field(s) are used to define the bar legend (a color for each column) and the Row field(s) are used for the X axis Click the “Switch Row/Column” button, which will transpose the Row and Column fields The

resulting chart should now look like Figure 5-28

Figure 5-28 Switching the Row and Column fields

This is a little bit easier to follow For the Classics category, for example, you can now see how each media type contributes to the summary totals Loans, Fees, and Overdue Notice the dropdown button

are included in the chart Click the CategoryDescription dropdown and unselect all of the categoriesexcept Classics, as shown in Figure 5-29

Figure 5-29 Selecting only the Classics category

Changing the Chart Type

With the data limited to a single category, you may want to use a different type of chart Click the

“Change Chart Type” button in the ribbon Select the Line type shown in Figure 5-30

Figure 5-30 Selecting a Line chart

The resulting chart is shown in Figure 5-31

Figure 5-31 The PivotChart View using a line chart

You can see from this chart that overdue fees have been charged for Hardback books, but no fees

have been charged for DVD videos or paperback books even though there have been overdue items of

these media types

 Note You will likely have different values in your database My purpose here is to give you an example of how

to read the chart

Now display the PivotTable View by selecting the PivotTable link from the View button Notice that this view now looks very different from where you left it This illustrates a very important point: The

PivotTable View and the PivotChart View use the same Row, Column, and Filter area definitions If you

change this configuration, it is automatically changed in the other, as well More subtle and perhaps

more significant, you can only have one PivotTable/PivotChart View for each table or query

 Caution You can define only one PivotTable/PivotChart View for each table or query The PivotTable and

PivotChart views share the same configuration; when you change one, the other is also updated

Exporting a PivotTable View to Excel

Access 2010 allows you to export a PivotTable or PivotChart view to Excel This will allow you to

manipulate the data and view using the Excel application As I mentioned earlier, the concepts are similar but the implementation is different

From the PivotTable View, click the CategoryDescription dropdown and select all categories Save the database and then click the “Export to Excel” button in the Design tab of the ribbon You will see a pop-up window warning you about possible compatibility issues, shown in Figure 5-32 Click the OK button

Figure 5-32 Compatibility warning

Access will then open the Excel application and create a PivotTable worksheet, as shown in Figure 5-33 Notice the similarities to Access 2010 and the differences

Figure 5-33 The PivotTable View in Excel

The most obvious difference is that the multi-field hierarchy is not as evident Notice that the CheckedOut By Month field is replaced by a set of fields, one for each of the data components such as Year, Quarter and Month

The raw data is also imported in the second worksheet, as shown in Figure 5-34

Figure 5-34 The underlying Excel data

Excel uses the raw data that the PivotTable is based on In order for the PivotTable to work, all of the raw data must be imported, as well You can use this approach create a new PivotTable and/or chart in

Excel using the data from Access and the PivotTable features from Excel

 Caution When you export data to Excel, this is a one-time operation Subsequent changes to the data in Access

are not pushed to Excel using manual or automatic means The only way to update Excel is to re-import the data

• Data area: This contains the values that ate presented and normally use an

aggregate function to summarize the data

• Row and Column: Fields in these areas define the attributes that are used for

slicing and dicing the data

• Filter: (Optional) Fields in the Filter are used to limit the data that is being

presented

If you specify multiple Row or Column fields, they are added in hierarchical fashion allowing you to drill down from one attribute to the next The built-in By Month and By Week date fields are an excellent example of this

The most significant limitation to keep in mind is that you can only have one PivotTable/PivotChart View for each table or query The PivotTable and PivotChart views share the same configuration values; when you change one, both are updated If you want to create additional PivotTables, refer to Chapter 4 for instructions on how to create a query that joins several tables

You can also export the data and PivotTable to Excel and manipulate the presentation using the

Creating Forms and Reports

In Part 2, you created your database, designed the tables, and wrote data macros to implement many of the business rules You created queries to provide de-normalized views into your data, and even

designed a pivot table to analyze the data that is being collected Although still a bare-bones solution,

your database fulfils all the basics requirements In Part 3, however, you’ll put flesh on those bones and create a rich user experience

Chapter 6 will show you how to use the built-in form templates to easily generate many of the

simpler forms Chapters 7, 8, and 9 demonstrate how to build more complex forms from scratch This

will demonstrate a lot of handy tricks for creating useful forms Chapter 10 will show you how to create menus and navigation pages that will guide the user to the provided features In Chapter 11, you’ll focus

on the visual, branding aspects of your application, including themes, graphics, and background images Finally, in Chapter 12, I’ll show how to create reports, which are essentially forms that are designed for print output

Standard Forms

One of the really great features of Access is that it can generate forms for you based on your table design This is another good reason for starting with a well thought out data schema In this chapter, I’ll

demonstrate several common form patterns that will satisfy many of your UI requirements These are

created using standard form templates or the Form Wizard, and do not require writing any code

This chapter will also provide a foundation that applies to both these simple forms as well as

advanced custom forms In subsequent chapters, I’ll show you how to design forms yourself and use

macros and VBA code to implement more complex solutions These custom forms are based on the

same general principles that I will explain in this chapter

Creating a Single Form

We’ll start by creating a simple form to display records in the Category table

Using the Form Wizard

From the Create tab of the ribbon, click the Form Wizard button In the first dialog box of the Form

Wizard, select the Category table, and then move the CategoryCode and CategoryDescription fields to the Selected Fields list, as shown in Figure 6-1

Figure 6-1 Selecting the record source for the form

Each form is based on a single table or query, and the first step in designing a new form is to specify which will be the source for this form After selecting a table or query from the dropdown list, all the available fields will display You can then select all of the fields to be included on the form or just a subset of them

■ Caution If your form will be used to add records, you should generally use a table for the source, rather than a query Queries usually supply only a subset of fields or rows and often use multiple tables All of these

characteristics are problematic when inserting records That is not to say that you cannot use a query; however, if you use a query for a form that allows new records, make sure that every required field is included on the form or has a default value assigned Otherwise, the form will not be able to save a new record

Notice that the primary key was not included in this form; this is a common design practice As I discussed in Chapter 2, the primary key is a surrogate key generated by the database engine to ensure uniqueness In many cases it is not meaningful to the end user, so there is no need to display it in that scenario

In the second dialog, you’ll need to choose how you want the fields organized on the form As shown

in Figure 6-2, there are four layout options available I will explain these choices later in this chapter Because this form only has two fields on it, just leave the default option of Columnar and click the Next button

Figure 6-2 Choosing the desired layout option

In the final dialog box, enter Category for the title of this form For the radio options, select the first

option, “Open the form to view or enter information,” as shown in Figure 6-3

Figure 6-3 Specifying the form name

The new form should look like Figure 6-4

Figure 6-4 The initial Category form

In this simple form, a single record is shown Notice the record navigator at the bottom of the form You can use this to move to the first, previous, next, or last record in the table The last control in this group will display a blank record for adding a new category

Using the Available Views

Just like with tables and queries there are several views available when working with a form To display all the view options, perform the following steps:

1 Click the Design View button in the ribbon If the Property Sheet is not

currently visible, click the Property Sheet in the Design tab of the ribbon There

is a dropdown list at the top of the Property Sheet that you can use to select the object that you want to view You can select the Form, any of the sections such

as Form Header or Detail, or one of the individual controls Because there are a lot of properties, these are grouped into separate tabs

2 Select the Form object and the Format tab There are several properties that

control what views are allowed for this form The Form Wizard generates the form with the Datasheet View turned off Change this value to Yes as shown in Figure 6-5

Figure 6-5 Allowing the Datasheet View

Notice that the View options in the ribbon now has four options, which are shown in Figure 6-6

Figure 6-6 The allowed views

Every form usually has two modes that it can be viewed in; Form View and Datasheet View You’ve

already seen the Form View In this view, a single record is displayed and a record navigator control is

used to move through the available records Each field is represented by an appropriate data-bound

control, such as Text Box, Check Box, or ComboBox depending on the type of data contained in the field

In addition, Label controls are used to annotate what each data control is for All of these controls are

arranged on the form

Select the Datasheet View from the ribbon, which should look like Figure 6-7

Figure 6-7 Displaying the Datasheet View

The Datasheet View of a form looks very much like the table when it is displayed in the Datasheet

View In this view, you can re-order the columns by selecting one and then dragging it to the desired

position You can change the width of the column by clicking the gridline and dragging it left or right

The column headings are defined by the Datasheet Caption property Let's change them now, with the

following steps:

1 Select the CategoryCode column and then, in the Property Sheet, select the

Other tab

2 The default value of the Datasheet Caption property is blank When this is the

case, the heading text is defined by the Control Source property, which is theassociated column of the underlying table The Caption that was defined for

that column will be used as the column heading Enter Code for the Datasheet

Caption property

3 Likewise, for the CategoryDescription column, enter Description for the

Datasheet Caption property

■ Note The configuration of the Datasheet View is independent of the Form View Changing the order of the

columns, the column widths, or the column headings has no effect on the layout of the Form View If you allow both views of your form, you should check the layout of the Datasheet View and make sure it looks like you want it

to

The Layout View and Design View are used to design and modify the form You will use these viewsextensively in subsequent chapters as you build custom forms The Design View allows you configure allaspects of the form The Layout View is an interesting and useful view It looks like the Form view anddisplays the fields just like the Form View would, but it also allows you to add and rearrange controls It

is essentially a WYSIWYG editor

Sorting the Records

To sort the records, click the dropdown icon next to the Description column and click the Sort A to Zlink, as shown in Figure 6-8

Figure 6-8 Sorting the Datasheet View

This will display the records in alphabetical order based on their descriptions This change is

reflected on both views You can verify this by switching to the Form View; the records should be in the

same order as in the Datasheet View Go to the Design View and select the Data tab of the Property

Sheet Notice the Order By property has been populated, as shown in Figure 6-9

Figure 6-9 The Order By property

Using Split Forms

All forms are based on these two display modes, Form View and Datasheet View However, there are also two variations of these that are a composite of both views The first is called Split Form, which shows

both views simultaneously The other is a Continuous Form, which combines features from both the

Datasheet and Form views

The Split Form is a really useful feature, especially for smaller tables It enables you to see all the

records in a compact Datasheet View At the same time, a single record can be viewed and modified in

the more user-friendly Form View A good example would be for longer text fields The Datasheet View

will probably only show the first few words but the Form View can display the entire text on multiple

lines, with scrollbars if necessary

Generating the Media Form

You’ll now create a Split View for the Media table with the following steps:

1 Close the Category form and any other tabs that may be open

2 Select the Media table in the Navigation pane

3 From the Create tab in the ribbon, click the More Forms dropdown and then

click the Split Form link, as shown in Figure 6-10

Figure 6-10 Creating a Split Form

This will generate a form based on the current table, which should look like Figure 6-11

Figure 6-11 The initial Split Form

■ Tip Creating a form using the Split Form button does not start the Form Wizard, which allows you to configure

how the form will be generated Instead it creates a form based on the currently selected table and includes all the available fields You need to make sure you have the correct table selected in the Navigation pane before using

this option If you create a form from the wrong table, just delete it and try again

Modifying the Form Fields

The form was generated using all the fields You’ll need to remove the MediaID field from both forms; to

do so, right-click the MediaID column in the Datasheet View (the lower portion of the form) and click the

Delete link This will also remove this column from the Form View

Just like with the previous form, you configure the layout of both the Form View and Datasheet View separately We’ll start with the Form View

1 The label for the RenewalsAllowed field is a little long (How many times can a

loan for this type of item be renewed?) To make this form look better, you’ll

use the Layout View to resize the controls From the Design tab of the ribbon,

click the Layout View button

2 Select the label control for the RenewalsAllowed field, which will highlight the

control with an orange border

3 Resize this control so it is about half as wide and twice as high The form

should look like Figure 6-12

Figure 6-12 Resizing the label control

4 Now adjust the column heading in the Datasheet To do that, use the Property

Sheet and select the RenewalsAllowed control

5 In the Other tab, enter Renewals for the Datasheet Caption property

6 Save the form and select the default form name Media when prompted

Go back to the Form View to view the final version, which is shown in Figure 6-13

Figure 6-13 The final Media form layout

■ Tip If you remove a field from one of the views, it is automatically removed from both This happened, for example, when you removed the MediaID field Normally, both views will include the same fields However, there are a couple of ways around this if you want to have different fields in each view To remove a field from the Form View only, use the Property Sheet to set the Visible property to No The field will still be included in the Datasheet View, but both the field and its associated label will be hidden from the Form View To remove a field from only the Datasheet View, simply resize the column to a 0 width

Figure 6-14 shows the form with OverdueFee field removed from the Form View and the

RenewalsAllowed field from the Datasheet View

Figure 6-14 Updated form with fields removed

■ Tip In the Format tab of the Property Sheet, you can set the Split Form Orientation property The default value is Datasheet On Top, but you can change this to put the Datasheet View on the top if you prefer You can also put it

on the right or left

Using Continuous Forms

The other variation is called a Continuous Form It’s like a Datasheet View in that all records are

displayed sequentially However, each record is displayed as a collection of controls just like the Form

View It is basically the Form View, except instead of only displaying a single record, the form controls

are repeated over and over again Obviously, this won’t work very well for long forms, but it can be useful for relatively short forms

Generating the InventoryItem Form

You create a Continuous Form just like the Form View that you created at the beginning of the chapter Then you have to the change the Default View property to Continuous Form You’ll now create a

Continuous Form for the InventoryItem table following these steps:

1 From the Create tab of the ribbon, click the Form Wizard button In the first dialog box, select the InventoryItem table and include all the available fields as shown in Figure 6-15

Figure 6-15 Selecting the InventoryItem table

2 In the second dialog box, select the Tabular layout, as shown in Figure 6-16 The Tabular layout is the best choice if you’re planning to use a Continuous Form It was designed specifically for that purpose

3 In the final dialog box, leave the default form title as InventoryItem, as shown

in Figure 6-17 Select the second radio option, which is to modify the form’s

design This will cause the new form to be opened in the Design View instead

of the Form View

Figure 6-17 Specifying the form title

The form should now be displayed in the Design View and look similar to Figure 6-18

Figure 6-18 The initial form in Design View

The first thing you’ll probably noticed is that the Label controls are in the Form Header rather that

the Detail section In a Continuous Form, only the Detail section is repeated for each record The Form

Header and Form Footer are only displayed once Typically you will want to put the labels in the header

to save “space” in the repeated section This will help you keep the Detail as thin as possible However,

you don’t have to do this; you can also put some or all of the labels in the Detail section if you want

■ Tip You cannot drag a control from one section of a form to another If you want to move a label from the Form

Header section to the Detail section, right-click the control and click the Cut link Then right-click in a blank area of the Detail section and click the Paste link

Also, the default layout has all of the fields on a single row, much like a datasheet Again, you don’t have to keep them that way; you can arrange them in any way you want to In general, however, you will want to keep the Detail section thin, especially if you expect numerous records to be included

USING THE MULTIPLE ITEMS TEMPLATE

Access often provides multiple ways to accomplish the same thing Instead of using the Form Wizard, you could have selected the InventoryItem table in the Navigation pane and then click the Multiple Items button in the Create tab of the ribbon, as shown in Figure 6-19

Figure 6-19 Using the Multiple Items button to create a form

This would create a new form that is very similar to the one created through the Form Wizard

Designing the InventoryItem Form

It is helpful to think through how a form will be used; specifically, is it for view only or will it be used to add or update records The first two forms that you created were designed to view, add, change, and delete records from the Category and Media tables The InventoryItem form will be primarily used for viewing but will allow some restricted updates

In Chapter 4, you created an append query that is used to insert a record into the InventoryItem

You will eventually add a button to an Item form that will execute this query to add a copy of that item to the inventory Also, the ItemID should not be editable once the record is created Likewise, the Status

field is controlled by the data macros that you implemented in Chapter 3 The only user-modifiable

fields on the form are Condition and Comment

This InventoryItem form will be used as a subform, which I will explain later in this chapter It will

be used to show the InventoryItem records for a specific item Since the associated item is inferred by

the context in which this subform is placed, you can remove the ItemID from this form Also, the

CurrentLoanID field is not necessary for this purpose The Status field was generated as a ComboBox

control to allow the desired value to be selected Because this should not be editable, you’ll want to

replace this control with a TextBox control This will display the current value without implying to the

user that it can be modified

Modifying the Form Fields

From the Design View, make the following changes:

1 Delete the ItemID ComboBox control Notice that its associated label was not

also removed Because they are in different sections, they are not linked

together You’ll need to manually delete the Label control as well

2 Delete the Status ComboBox control (leave the label)

3 From the Design tab of the ribbon, click the TextBox button Then click in the

Detail section, holding the mouse button down and dragging it to form a

rectangle in the same location and about the same size as the previous

dropdown list control In the Other tab of the Property Sheet, enter Status for

the Name property In the Data tab, select Status from the Control Source

property

4 The new Textbox control will have added an associated Label control Delete

this, as it is not needed

5 On both the InventoryItemID and Status controls, set the Locked property to

Yes You can find this in the Data tab of the Property Sheet

6 Change the Caption property of the InventoryItemID label to ID and set the

Text Align property to Left

7 Remove the CurrentLoanID ComboBox control as well as its associated label

8 Rearrange the controls in both the Detail and Form Header section to remove

the empty spaces

The form in Design View should look similar to Figure 6-20

Figure 6-20 The completed Design View

Select the Form object in the Property Sheet and then select the Format tab Notice that the DefaultView property is already set to Continuous Form This is set by the Form Wizard whenever you use theTabular layout

■ Note You can change the Default View to Single Form if you want to see what the form would look like as a

Single Form This does not affect the design or layout of the form Make sure you change it back to Continuous Form if you do change the Default View

Save the form changes and select the Form View from the ribbon The final form should look likeFigure 6-21

Figure 6-21 The final InventoryItem form

Understanding the Layout Options

Before I explain the final form that you’ll create in this chapter, I want to review the layout options that

are provided by the Form Wizard You use the first dialog box to define the data source for the form

Each standard form uses a single table or query You specify which one to use for the form and then

decide which fields of that table or query to be included

You use the second dialog box to indicate one of four layout options, which are:

• Columnar

• Tabular

• Datasheet

• Justified

When you select the associated radio button, the image changes to give you a visual representation

of how your form will look

Using the Tabular Layout Option

As I just demonstrated, the Tabular layout is used for generating a Continuous Form The labels are

placed in the Form Header and the data bound controls are aligned horizontally in a single row This is

presented in the Form Wizard with the graphic shown in Figure 6-22

Figure 6-22 The Tabular layout

As I mentioned earlier, Continuous Forms don’t have to follow this pattern You can include labels

in the Detail section and arrange the data bound controls in any manner you wish Also, when you chose the Tabular layout, the Default View property of the form is set to Continuous Form

Using the Datasheet Layout Option

Similarly, the Datasheet layout should be used when you want to create a form that is viewed in the Datasheet View The graphic shown in Figure 6-23 portrays this The labels are at the top, like the Tabular layout, but there are also record selectors on each row

Figure 6-23 The Datasheet layout

When you use this option, the Default View property of the generated form is set to Datasheet View However, you can choose to view the form using the From View If you do, you’ll notice that the form layout look just like forms generated with the Columnar layout, which I’ll describe next In fact, the Datasheet and Columnar options generate the exact same form, except that the Default View property is set to Datasheet View with the former option and Form View with the later

Using the Columnar Layout Option

The last two layout options, Columnar and Justified are used when creating forms that will be viewed in the normal Form View You used the Columnar layout when creating the Category form This layout creates a label and its associated data-bound control side-by-side on the form Each field is stacked vertically, which results in a column of labels and a column of controls The image shown in Figure 6-24 represents this arrangement

Figure 6-24 The Columnar layout

This graphic implies that there can be multiple pairs of columns; however, the Form Wizard only

creates a single pair of columns You can arrange this into multiple columns in the Layout View using a

Layout control, which I’ll explain later

Using the Justified Layout Option

The final layout choice is called Justified It generates a label that is directly above its associated

data-bound control for each field Instead of being stacked in columns, these pairs are arranged left-to-right

like text on a page This is demonstrated in the associated graphic shown in Figure 6-25

Figure 6-25 The Justified layout

In some ways this may seem like a more desirable arrangement, as well as the most efficient use of

space

■ Caution Keep in mind that if you plan to use a layout control, which I’ll explain next, the Justified layout is not

compatible When converting to a layout, the fields will be re-arranged using Columnar format before being added

to the layout

Using a Layout

Access provides a facility for easily arranging controls on a form that is often referred to as a layout It is a grid that contains cells where you can insert controls By placing labels and data-bound controls into a grid, you can easily format or resize an entire column or row and keep everything aligned properly You may have noticed that the controls in the Media form were placed in a grid However, the Category and InventoryItem forms do not do this These were generated using the Form Wizard, which does not use a layout You’ll fix that now

1 Open the Category form using the Design View

2 Select all the controls in the Detail section You can do this quickly by dragging

the mouse around a rectangle that includes all of the controls Then, from the Arrange tab of the ribbon, click the Stacked button, as shown in Figure 6-26

Figure 6-26 Using the Stacked button in the Arrange tab

3 You can switch to the Layout View and resize the grid columns, if necessary

Save the form and then switch to the Form View to see how the form looks

4 Open the InventoryItem form in the Design View In this form the labels are in

the Form Header

5 Select both the labels and the data-bound controls For this form, click the

Tabular button in the Arrange tab of the ribbon

6 Switch to the Layout View and resize the columns Notice that the labels in the

Form Header are kept aligned with the associated control as you size each field The final layout should look like Figure 6-27