Simple Database Programming concept in C#.

SqlConnection conn = null;
try
{
conn = new SqlConnection(”Data Source=localhost; Initial Catalog=cs466; Integrated security=SSPI”);
conn.Open();

// Insert users
string ins = “insert into users values(@name, @password, @role)”;
SqlCommand cmdINSERT = new SqlCommand(ins, conn);
cmdINSERT.Parameters.AddWithValue(”@name”, “rajan”);
cmdINSERT.Parameters.AddWithValue(”@password”, “flower”);
cmdINSERT.Parameters.AddWithValue(”@role”, “guest”);
cmdINSERT.ExecuteNonQuery();

// Delete users
string del = “delete users where name=@name and password=@password”;
SqlCommand cmdDELETE = new SqlCommand(del, conn);
cmdDELETE.Parameters.AddWithValue(”@name”, “rajan”);
cmdDELETE.Parameters.AddWithValue(”@password”, “home”);
cmdDELETE.ExecuteNonQuery();

// Update users
string upd = “update users set password = @password where id = @id”;
SqlCommand cmd = new SqlCommand(upd, conn);
cmd.Parameters.AddWithValue(”@password”,”rakesh”);
cmd.Parameters.AddWithValue(”@id”, 2);
cmd.ExecuteNonQuery();

// Select users
string sql = “select * from users”;
SqlCommand command = new SqlCommand(sql, conn);
SqlDataAdapter da = new SqlDataAdapter(command);
DataSet ds = new DataSet();
da.Fill(ds);
DataTable dt = ds.Tables[0];
foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < dr.ItemArray.Length; i++)
{
Console.Write(”{0} “, dr[i]);
}
Console.WriteLine();
}

}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
conn.Close();
}