在选择的陈述中使用多个行

Question

I have a select satement in C# and i was wondering if it is possible to use diaplay email and username in two diffrent label.

Below is the query:

SqlDataReader reader;
string sendMessage = "SELECT Email, username FROM aspnet_Membership WHERE UserId = @UserId";
using (SqlConnection myConnection = new SqlConnection(connectionString))
{
    myConnection.Open();
    SqlCommand myCommand = new SqlCommand(sendMessage, myConnection);
    myCommand.Parameters.AddWithValue("@UserId", newUserId);
    ArrayList emailArray = new ArrayList();
    label1 = myCommand.ExecuteReader();
    label2 = myCommand.ExecuteReader();
}

Thank you

Answer 1

Yes, of course, but you need to call just one time the ExecuteReader and then use the SqlDataReader returned to get the field values of the current record. (Of course the text returned by the reader should be assigned to the Text property of the label, not to the label itself)

string sendMessage = "SELECT Email, username FROM aspnet_Membership WHERE UserId = @UserId";
using (SqlConnection myConnection = new SqlConnection(connectionString))
using (SqlCommand myCommand = new SqlCommand(sendMessage, myConnection))
{
    myConnection.Open();
    myCommand.Parameters.AddWithValue("@UserId", newUserId);
    using(SqlDataReader reader = myCommand.ExecuteReader())
    {
         while(reader.Read())
         {
              label1.Text = reader.GetString(reader.GetOrdinal("EMail"));
              label2.Text = reader.GetString(reader.GetOrdinal("UserName"));
         } 
   }

}

Also, do not forget to put the disposable objects like the command and the reader inside the appropriate using statement

Answer 2

Just call ExecuteReader once, and call Read method.Then you can get the values using indexer:

reader = myCommand.ExecuteReader();
reader.Read();
label1.Text = reader["Email"].ToString();
label2.Text = reader["username"].ToString();