Microsoft Access is an application used to create computer
databases that can be used on a Microsoft Windows operating system, on a web
site, or on portable medium.
Various Libraries for a Database |
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Because there are many requirements and many options for
computer databases nowadays, there are also various techniques of creating a
database. Still, by its basic definition, a database is primarily one or more
lists. How the list(s) is (are) created can depend on various circumstances. To
make it possible to create databases, various libraries have been developed and
you use one of these libraries to do a better job:
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Microsoft Access Object Library: Microsoft Access provides its own
mechanism for creating and managing a database. It provides most of the tools
you need to start and complete a database project. Microsoft Access is also
equipped with a library, the Microsoft Access Object Library that you can use to programmatically create and manage
databases. This library is already available to you so you don't have to
"load" it.
Microsoft Data Access Object: Microsoft Data Access Object,
or DAO, is a library that ships with Microsoft Access and allows you to create,
maintain, and manage databases. It also provides various means of performing the
necessary
operations on a database. Starting with Microsoft Access 2000, the DAO library
is always available but it is not automatically loaded (made available to a new
database). If you want to use, you must first add it to your project.
Microsoft ActiveX Data Objects: Microsoft ActiveX
Data Objects, also called ADO, is a library that was developed to allow
programmers with other environments to create and manage Microsoft Access
databases. To support this, it provides a driver that allows these other
programming environments to "attach" their applications to a Microsoft
Access database. Like Microsoft Access' own library, you can use ADO inside of
Microsoft Access to fully create and manage a database. Unlike DAO, starting
with Microsoft Access 2000, ADO is automatically loaded when you start a new
database so you don't have to add it to your project.
Microsoft ADOX: Microsoft ActiveX Data Object
Extensions for Data Definition Language and Security, also called ADOX, is an
addition to ADO. For example, since you cannot inherently create a Microsoft
Access database using ADO (that is, its objects), you would instead use ADOX.
ADO.NET: ADO.NET is the latest technique developed by
Microsoft and that is part of the .NET Framework. This technology allows you to
use one or more libraries of the .NET Framework and one or more of the languages
of the .NET Framework to create and manage your project. Although its name
includes ADO, ADO.NET is neither ADO nor a real library, it is a technique of
creating and managing databases. For example, while ADO contains objects and
collections, ADO.NET doesn't own anything.
Win32 API: A library is practically never complete.
To complement those cited above, you can use others. One the external libraries
you can use is called Win32. It belongs to Microsoft Windows and is already
installed with the operating system. Because most of its functions are written
in C, they cannot be directly used in a Microsoft Access database: you must
import them.
Other Libraries: Besides the above libraries,
Microsoft and companies other than Microsoft regularly published other libraries
you can use to perform some tasks in your Microsoft Access databases. Additionally,
you can also create your own library, or ask someone else to create libraries
for you, using languages such as C, C++, Delphi, etc.
In our lessons, we will be using Microsoft Access to
create computer-based databases. There are different techniques you can
use to launch it. Probably the easiest technique consists of clicking
Start -> (All) Programs -> Microsoft Access. You can also create a
shortcut to your desktop or above the Start menu.
When Microsoft Access starts, it immediately displays
a dialog box that allows you to specify the primary operation. |
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The Microsoft Access Interface |
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Like a regular multiple application interface (MDI),
Microsoft Access displays a menu in its top section. This main menu is
made of the most regular categories such as File, Edit, View, Window, and
Help:
To support databases, the main menu of MS Access also
includes items such as Insert or Tools, etc. When you click an item from
the main menu, it displays its sub-items. At times, the menu will depend
on other windows that display on the screen.
Under the main menu is a toolbar. The most regularly
displayed toolbar is called Database as you can see its check box if you
right-click a toolbar or the main menu:
If you are working on a database, Microsoft Access may
display the Database window:
In the lower section of the Microsoft Access
interface, it displays a status bar with various sections.
Practical
Learning: Starting Microsoft Access
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Most of the time, you can create a good performing database
using only what Microsoft Access natively has to offer. In some other cases, to create
a more complex database, you would have to write code. To support this,
Microsoft Access ships with, and installs a programming environment named
Microsoft Visual Basic. This is a flavor of the popular Microsoft Visual Basic
with everything you need to write any type of code to complement your
application.
There are various ways you can open Microsoft Visual Basic.
The easiest way consists of clicking Tools -> Macro -> Visual Basic
Editor. If you had no object selected, Microsoft Visual Basic would appear
empty:
If you had an open database when you accessed
Microsoft Visual Basic, it would appear with non-empty windows that
would display contents related to the database in Microsoft Access:
Microsoft Visual Basic appears like a class
application with a menu, a toolbar, and additional window. To know what a particular
button is used for, position your mouse on top of one and view a tool tip.
Practical
Learning: Opening Microsoft Visual Basic
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- On the main menu of Microsoft Access, click Tools -> Macro -> Visual
Basic Editor
Visual Basic Child Windows |
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Almost any section of Visual Basic is dockable,
which means it can be moved on the screen to another location.
The Project Explorer displays the coding
objects available for your database. If the Project Explorer is not displaying,
on the main menu, click View -> Project Explorer.
This window object is
usually on the left of the window. To move it, you can click its
title bar under the Standard toolbar, hold your mouse down and
drag to the desired location. To position it back
to its previous location, you can double-click its title bar. To expand or collapse the folders
tree, click the Toggle Folders button.
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Every object and item of your database has
characteristics, called properties, associated with it. You control those properties
when you design the object. For example, when you are
designing a form in Microsoft Access, you define what its
caption would be. You can as well have access to these
properties in Microsoft Visual Basic. These properties are
displayed in the Properties Window when the object is
selected.
Since the Project Explorer and the Properties Window
usually share the same section of the window (it is better
that way), you can shrink one and heighten the other. To do
that, position the mouse on the gray bar between both windows.
When the mouse pointer turns into a short line with double
arrows, click and drag. |
The Code window is the area where you will mostly
be working, this is the largest section of the studio. It is mainly made
of three sections:
On top, there are two combo boxes. To know the
name of a combo box, you can position the mouse on it and a tool tip
would come up. The Object
combo box allows you to select a particular object and access its
events, actions that the object can launch. The Procedure combo box
allows you to select an action, related to the object in the Object
combo box, that you want to control.
The big and wide area is where you will be
writing code. There are one vertical and one horizontal scroll bars
that allow you to move left, right, up, and down in case your code
is using more space than the code window can display. The Code
Editor uses default colors to show the code. To customize these
colors, you can use the Editor Format property page of the Options
dialog box that you can access from the Tools -> Options... on
the main menu.
There are two small buttons on the left side of
the horizontal scroll bar. The Full Module View button is used to
display the whole associated with an object. The Procedure View
button will display only the public procedures associated with the
database.
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The Immediate window is used to test code when
necessary. To display it, on the main menu of Microsoft Visual Basic, you
can click View -> Immediate Window |
Practical
Learning: Using Microsoft Visual Basic Windows
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- To display the immediate window, on the main menu of Microsoft Visual
Basic, click View -> Immediate Window
- To use it, in the Immediate window, type ?NOW and press Enter
Closing Microsoft Access and Visual Basic |
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The version of Microsoft Visual Basic we are using here is "For
Applications". Indeed, you can create a fairly functional
application with this version, but it is related to Microsoft Access
(or Microsoft Office). When you are in the editor window of Microsoft
Visual Basic, you can get back to Microsoft Access either from the
View Microsoft Access button on the Standard toolbar, or by clicking
a Microsoft Access object on the Taskbar. The shortcut to get back
to Microsoft Access is Alt + F11.
You can close Microsoft Visual Basic any time and
keep Microsoft Access running. To do this, on the Standard toolbar of Microsoft Visual Basic,
you can click the
View Microsoft Access button to get back to the database. On the
other hand, if you close Microsoft Access,
Microsoft Visual Basic will be closed also.
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