EGR 141 Computer Problem Solving in Engineering and Computer Science

1
EGR 141Computer Problem Solving in Engineering
and Computer Science

• Interfacing with a Database
• in Visual Basic .NET 2005

2
Three components

• Database Connection
• A connection to the database file
• Table Adapter
• A connection to a specific Table
• Data Set
• A recordset of a Table
• Can be the whole table or some subset of a table
  for example

3
Three Steps

• Connect to the Database
• Setup the Table Adapter using one or more tables
• Create the Data Set

4
Connect to the Database
Click on the DataGridView control and drag and
drop it on your form. We will establish a
connection, setup a Table adapter, and create a
dataset using this control.
5
Connect to the Database
Using the wizard, click the pull-down arrow next
to Choose Data Source and select Add Project
Data Source
6
Connect to the Database
Select Database and click NEXT Then, click the
New Connection button and select Microsoft
Access Database File and click Continue
7
Connect to the Database
Using the Browse button, search for the
Database File Name. Click Test Connection to
make sure the connection works properly. Click
OK
8
Connect to the Database
If you want VB .NET 2005 to make a copy of your
database in your project directory so that all of
the files, including the database, are in one
folder on your hard drive, click YES. I would
recommend doing this so that your project can be
transferred to your USB stick and other computer
easily. Remember, no matter where you originally
put your database file, the one that your program
is using will now be in your project directory.
9
Connect to the Database
Click Next to save the Connection to the database
10
Create the Table Adapter Dataset
Next, we will setup the table adapter and dataset
in one step. Use the plus sign to expand the
list of Tables and select the Table(s) that we
want to use in our program. Note the name of the
dataset that will be created. Click Finish.
11
Back at the Form

• Back at your form, you will notice that the Data
  Grid shows the columns in the Data Set that was
  just created.
• More importantly, notice that 3 things have been
  created for you to reference in your program
• Database Connection (Source)
• Table Adapter
• Data Set

12
Data Grid

• If you do not wish to use the visible Data Grid,
  you may turn it invisible by setting the VISIBLE
  property to FALSE or simply delete it from your
  form. The connection, adapter, and data set will
  remain.
• Database Connection (Source)
• Table Adapter
• Data Set

13
Objects for using the database
Connection to database
Connection to table
A dataset to work with
Notice that VB .NET added an underscore to your
dataset
14
Fill the Table Adapter
Fill the data adapter with the dataset on the
FORM LOAD event. Notice that the wizard put the
code there automatically!
15
Code for manipulating records
Dataset name Table name Field Name
Using WITH we can avoid retyping _141DataSet and
just start with the dot
16
Code for manipulating records
Dont forget to Update your Database using the
Table Adapter!