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Data Adapter Configuration Wizard
In this section we will create our own data adapter, a built-in feature that comes
with Visual Basic .NET and work with it. We will create our own table and access data
from the newly created table. To start, create a new database in Access, name
it as Books, create a table, Table1 with some columns in it and make sure the
database is in the C: drive of your machine. To start creating your own DataAdapter,
open a blank form and add a button (Button1) and a DataGrid control to it from the
toolbox. Our intention here is to display the table or some columns from the table
which we created in Access in the DataGrid control when Button1 is clicked. To display
that, click on the Data tab in the toolbox and double-click OleDbDataAdapter object.
We are using OleDbDataAdapter here as we are working with an OleDb data source. After
you select OleDbDataAdapter from the data tab in the toolbox it gets added to the
component tray beneath the form and opens the Data Adapter Configuration Wizard dialogue
which looks like the image below.
The DataAdapter Configuration wizard let's you customize your data adapter as you
want, example, displaying the whole table or displaying selected columns from
the table and so on. Click the next button in the Data Adapter Configuration wizard
to select the data connection you want to use. The dialogue that opens look
like the image below. It allows you to choose the data connection.
Since we are working with the table we created, click the "New Connection"
button in this dialogue box which opens the Data Link properties window.
The Data Link Properties window looks like the image below.
In the Data Link properties window, select the Provider tab and select "Microsoft
Jet 4.0 OLE DB Provider" from the list of available providers. After selecting
the provider, select the Connection tab. Click on the ellipse where it says "Select
or enter a database name" and browse for the database on the local drive. Since
we are working with our own database (Books.mdb) located on the C: drive select that.
Click on the "Test Connection" button to test the connection and if the connection
succeeds click OK. Clicking OK display a dialogue box like the image below.
It's at this stage we will generate the SQL Statements to be used with this
data adapter. Click next on this dialog box which takes you to another dialogue box
like the image below.
It's here we build our SQL Queries. We can display the entire table in the DataGrid
or just some columns from the table. To display data, click on the Query Builder button
on this dialog box to build your queries. Once you click that button a new dialog
box opens up with a list that displays all the tables in the database with which we
are working. In this case it displays only one table as we created only one table
in the Books database. Select Table1 and click Add. Table1 is added to the Query
Builder window. You can select entire table to be displayed in the DataGrid or
just some columns. To display entire table in the DataGrid select the checkbox named
"All Columns" in the small dialog named "Table1" which automatically
builds the SQL statement for us. If you want to display specific columns from the
table in the DataGrid check on the columns you want to display. Once you finish with
your selection, click next. The dialogue box that opens when you click next looks
like the image below.
This dialogue lists the configuration of the data adapter and the results. Click
finish to close the Data Adapter Configuration wizard.
That creates the data adapter, DataAdapter1, we need. Next step is to create a DataSet
and connect this DataSet to the DataGrid using the DataSource and DataMember properties.
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