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Microsoft Access 9. Automating Tasks With Macros. Design a switchboard and dialog box for a graphical user interface. Database developers interact directly with Access.
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Microsoft Access 9 Automating Tasks With Macros
Design a switchboard and dialog box for a graphical user interface • Database developers interact directly with Access. • However, often you do not want the user of the database to interact directly with Access; rather, you would provide an interface that removes the user away from the Access interface. • A Graphical User Interface (GUI) is a collection of windows, menus, dialog boxes and other graphical components used to communicate with a program. • Often, the first view of a custom GUI is a switchboard.
What is a switchboard? • The switchboard is a form that opens when you start the underlying database and is usually used to provide the user with a set of choices. • This provides a well-organized interface for the user and eliminates the need for them to interact directly with the database window. • This also makes it possible to hide the functionality from the user so that they cannot make changes to the database objects. • The form you create for the switchboard is called a dialog box, which asks for user input in the way of a selection.
An example of a switchboard The figure below is an example of a switchboard form. The user would use this form to open the various objects in the database. Notice that this switchboard provides command buttons to provide access to all the options available to the user.
Run and add actions to macros • You can create a macro with a series of actions that will repeat these commands whenever it is invoked. • An action is an instruction to Access to perform an operation, such as opening a form or displaying a query. • You can also automate tasks with Visual Basic for Applications (VBA) but it is easier for a beginner to create macros. • With macros, you can simply select the actions you want from a list of actions. • Once the macro has been created, you can add actions to it by editing the macro in the Macro window.
Use the Macro window to add actions • It is within the Macro window that you will supply the action name (chosen from a list), any comments you want to make, and the arguments for the action. • Arguments are additional facts needed to run the action. • Each type of action has its own set of arguments. • A commonly used action is the Msgbox action, which will display a message to the user by way of a small form. • Another commonly used action is the FindRecord action that will find the first record matching a set of criteria.
The Macro window This figure shows the Macro Window. In this window you can add macro actions and set the arguments for the macro actions. Notice that each action has a comment column. This column is used to document the macro. It is a good idea to write a comment about how this particular action will be used. Notice also the lower section of the window. This section contains the properties for the currently selected action.
Single-Step a macro • When you run a macro, the series of actions are executing one after the other. • When you are testing a macro, sometimes it is useful to run the macro one step at a time. • This is called single stepping and causes the macro to perform one action, then waits for you to step to the next action. • This allows you to gain a clearer view of how the macro is working. • When you single step through a macro, Access displays a dialog box called the Macro Single Step dialog box.
Use the Macro Single Step dialog box • This Macro Single Step dialog box displays details about the next action in the macro. • You have three choices as to how you want to respond: • You can step through the macro one step at a time • You can halt the macro • You continue the macro • Single-stepping is used to help you determine if you have placed the actions in the right order and whether the actions are working as you expect them to.
The Macro Single Step dialog box The following figure shows the Macro Single Step dialog box. Notice that the dialog box provides information about the current macro action. Notice also that you have three command buttons from which you will choose what to do next.
Create a macro • Start with a blank macro and then add the actions to it. • Drag an action from the database windows into the macro window. • Each type of object has a default set of arguments. • For example, if you drag a table into the macro window, the default arguments are to open the table in datasheet view in edit mode. • Drag as many objects as you want to the macro window. • You can either accept the default arguments or you can edit them to meet your needs. • Run the macro and observe the results of the macro.
Actions created by dragging specific objects The figure below lists different kinds of objects in Access along with the default action created by dragging one of these objects to a Macro window. It also lists the default argument values created when dragging these objects to a Macro window.
Tile windows to improve efficiency This figure shows the Macro window and the database window tiled on the screen. This is a great way to drag objects to the macro window because you can see them both at the same time.
Create macro groups • If you have several small related macros, you might consider grouping them together with other small macros in a macro group. • A macro group is a macro that contains other macros. • This makes it easier for you to maintain a large collection of macros.
Add a macro to a macro group • When you group macros, each individual macro within the group will have a name assigned to it. • The name consists of the name of the macro group, followed by a period, followed by the name of the individual macro. • When you add a macro to a macro group, you add a new name to the Macro Name column. • However, if you are simply adding an action to a macro within the group, you add only the new action in the Action column under the macro name.
A macro group with two macros In the figure below, you see an example of a Macro group window. Notice the new column added for the Macro name. Each macro in the group will contain a name in this column. Actions that will be taken within that macro will appear in the action column but without a name.
Add a command button to a form • On the toolbox, you have a command button tool that allows you to place a command button on a form. • You can use the Command Button Wizard to help you place the command button or you can simply place the command button yourself. • Click the command button tool on the toolbox, move your mouse to the form and draw a box where you want the command button to appear. • The default text on the command button will appear; however, you can change this and other properties on the command button's property sheet.
An Access Form with a command button In this figure you can see that a command button has been added to the form. Notice the command button tool on the toolbar, which was used to create the command button. Notice also that the control wizard should be turned off so that you can control what properties will be set for the command button.
Attach a macro to a command button • Once you have added a command button to a form, you can attach a macro to it. • In most cases you will attach the macro to the command button's OnClick property. • Whenever the user clicks on the command button, the attached macro will be executed. • To attach the macro to the command button, right click the command button and then click on Properties to display the command button's property sheet.
Modify a macro’s property settings • You can change the OnClick property to the name of the macro you want to run when the user clicks the command button. • In the property sheet you can change the Caption property, which represents what is printed on the command button. • If you prefer to have a picture on the button, you can choose one from the Picture Builder dialog box. • For example, if the button will print a record, you might want to add a picture of a printer on the button.
The Picture Builder dialog box In the figure below, you see the Picture Builder dialog box, which contains a list of pictures supplied by Access. You can choose one of these pictures to appear on your command button or you can add a picture of your own.
Create a dialog box form • A dialog box is actually a form with which the user interacts. • You can add many different controls to the form such as command buttons, list boxes, text boxes, labels, etc. • To create a dialog box, you begin by adding a blank form. • You will probably want to change some of the form properties before you begin adding controls to the form • To change the text that appears in the form's title bar, enter a new value in the form's caption property • There are several other properties that you might want to set for the form depending on the particular application • Each property can be set on the Property sheet
An example of a dialog box In this figure, you can see an example of a dialog box. This particular dialog box list the queries in a database. In this example, the user can choose a query and then select one of the command buttons on the form to complete the action on the selected query.
Dialog box properties, settings, and functions This figure shows the properties and their values for the Queries dialog box form shown in the previous slide. Note that this is just an example. You might make different selections based on the application you are working on.
Add a list box to a form • On your dialog box, you might want to offer the user a list of choices. • A list box is a control that displays a list of values that a user can brows through. • You will usually add a label close to the list box to indicate what is contained in the list box. • To add a list box to a form, choose the List Box tool on the toolbox and then move your mouse to the form in the position where you want the list box to appear. • Once the list box is on the form, it can be sized and moved around just as you would any other control.
A list box on a form in Design View In the figure below, a list box has been added to the form. Notice that the list box has an attached label. In this example, the attached label will be removed because a label has already been added to the form.
Use an SQL statement to fill a list box with object names • The standard language for querying, updating, and managing relational databases is SQL (Structured Query Language). • Whenever you create a query in Access, Access is creating SQL statements to display datasheets according to the Query specification. • If you want to view these SQL statements for a query, you can choose SQL view from the View menu. • SQL uses the SELECT statement to specify what data is retrieved from a database and how it presents the data.
Understanding SQL statements • Just like any other language, there are rules of the language called syntax. • In order to program in SQL you need to learn the rules. • However, you can read an SQL statement created by Access and get a pretty good idea of what the statement does. • The SQL statements match up with the query specifications; every choice made in the design window is reflected in the SQL statement.
Access the MSysObject table • To use an SQL statement for a list box that will display a list of the queries in the database, you will need to retrieve the list of queries from the Access System Tables. • The particular table you must access is called the MSysObject table. • This table keeps track of all objects in the database. • The MSysObject table contains some special queries that you probably would not want to include in a list of queries.
An example of an SQL statement The figure below shows an example of an SQL statement with a query. Note that this statement was created by Access in the background. It is not mandatory that you know SQL in order to use Access.
Use the Switchboard Manager to create a switchboard • First, create all the macros you will need for the switchboard and then create the switchboard that will execute the macros. • You can use the Switchboard Manager to help you create the switchboard. • The Switchboard Manager allows you to specify what buttons should be on the switchboard and identify the command to execute when each of the buttons is clicked.
Switchboard considerations • The Switchboard Manager allows you to create only one switchboard for a database; however, the switchboard can contain multiple pages. • The main page of the switchboard will display when the switchboard opens. • You can place buttons on the main page that will cause other pages in the switchboard to open. • The switchboard manager is available on the Database Utilities option on the Tools menu.
An example of a macro group to be used for a switchboard This figure show a completed macro group containing six macros. These macros will serve as the actions for the switchboard.
The Switchboard Manager dialog box This figure is the figure page of the Switchboard Manager. Notice that the Main Switchboard has been created by default. You use this dialog box to add additional pages to the switchboard.
The completed switchboard This final figure shows the complete switchboard, which has buttons for each of the objects with which the user can interact.