manipulating database

Before coding the SQL for database manipulation, declarations are added to the code:

Dim connection As New Data.SqlClient.SqlConnection(ConfigurationManager.ConnectionStrings("connString").ConnectionString)
Dim command As New Data.SqlClient.SqlCommand
Dim reader As Data.SqlClient.SqlDataReader

The connString variable can be updated on the web.config file. Refer to this for a review on connection string.

Now, to insert data into a database table:

command = New Data.SqlClient.SqlCommand("INSERT INTO TABLE (COLUMN_1, COLUMN_2, COLUMN_3) VALUES (@COLUMN_1, @COLUMN_2, @COLUMN_3)", connection)
command.Parameters.Add("@COLUMN_1", Data.SqlDbType.VarChar).Value = textBox1.Text
command.Parameters.Add("@COLUMN_2", Data.SqlDbType.VarChar).Value = textBox2.Text
command.Parameters.Add("@COLUMN_3", Data.SqlDbType.VarChar).Value = textBox3.Text
command.ExecuteNonQuery()


Likewise, data inserted can also be displayed on asp.net controls:

command = New Data.SqlClient.SqlCommand("SELECT * FROM TABLE", connection)
reader = command.ExecuteReader()
If reader.Read() Then
textBox1.Text = reader("COLUMN_1")
textBox2.Text = reader("COLUMN_2")
textBox3.Text = reader("COLUMN_3")
Else
End If
reader.Close()

Both actions would require you to open your connection by:

connection.Open()

And then closing it after using:

connection.Close()