First off you need a connection string, it's good practise to store your connection strings in the web.config
file:
<connectionStrings>
<add name="MyConnectionString" connectionString="Data Source=putYourServerAndInstanceNameHere;Initial Catalog=putYourDatabaseNameHere;User ID=putYourSqlUsernameHere;Password=password" providerName="System.Data.SqlClient" />
</connectionStrings>
This is a direct child of the root <configuration>
element. For more information about connection strings, visit http://www.connectionstrings.com.
Then you'll need some imports in your code-behind, and you'll need to add them as references to your project if you haven't already got them in there:
Import System.Data
Import System.Data.SqlClient
Then we connect to the database and run our command, we use parameters because they're more secure.
'build the connection object using the string from the web.config file
Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings("MyConnectionString").ConnectionString)
'build the command object specifying the command text and the connection to use, conn
Using cmd As New SqlCommand("UPDATE Students SET RegistrationCode = RegistrationCode + @AmountToAdjust WHERE StudentID = @ID", conn)
'add the parameters needed by the command
cmd.Parameters.AddWithValue("@AmountToAdjust", amountToAdjust)
cmd.Parameters.AddWithValue("@ID", studentID)
'try to open the connection and execute the statement
Try
conn.Open()
cmd.ExecuteNonQuery()
Catch ex As Exception
'handle the exception here
End Try
End Using
End Using
Note that there is no need to use conn.Close()
here as the Using
statement will take care of that for you (SqlConnection's Dispose method closes the connection if it is still open).