CODEWITHSUNDEEP
c#.netsql-server
user3080000
user3080000

Reputation:

Add data to a table from database

I am new to .net and C# and I want to perform update/delete. I am using e template which has a table. I want to get data from database and display in that table and then perform update. 

protected void Page_Load(object sender, EventArgs e)  
{
   SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString);
   SqlDataReader rd;   
   SqlCommand comand = new SqlCommand();

   //open connection with database
   connection.Open();

   //query to select all users with the given username
   comand.CommandText = "select * from artikulli ";
   rd = comand.ExecuteReader();

   if(rd.HasRows )
   {
      while (rd.Read())
      {
         Row1.Items.Add(rd[0].ToString());
      }
   }

   connection.Close();
}

Row1 is the id of table row. I know that this is not the best way and it doesn't work.

I get this error:

CS0103: The name 'Row1' does not exist in the current context

My table row Row1 is declared as below:

<td id="Row1" style="width: 73px">&nbsp;</td>

Upvotes: 0

Views: 75

Answers (2)

Mike Guthrie
Mike Guthrie

Reputation: 4059

It's apparent, as you've admitted, you are new to C#, so there are a number of things to point out, as have been addressed in the comments.

  • HTML elements are not going to be visible to the code-behind without the runat="server" attribute. (This attribute is required for ASP elements.)
  • As marc_s pointed out, your database communication would currently produce a run-time error, as the SqlCommand was not given a connection.
  • At some point you must really familiarize yourself with the using statement.

To correct your code-behind, it should be more like the following:

protected void Page_Load(object sender, EventArgs e)
{
    using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["RegistrationConnectionString"].ConnectionString))
    {
        using (SqlCommand command = connection.CreateCommand())
        {
            //open connection with database
            connection.Open();

            //query to select all users with the given username
            command.CommandText = "select * from artikulli ";

            List<object> users = new List<object>();

            using (SqlDataReader rd = command.ExecuteReader())
            {
                if (rd.HasRows)
                {
                    while (rd.Read())
                    {
                        users.Add(rd[0].ToString());
                    }
                }
            }

            myGridView.DataSource = users;
            myGridView.DataBind();
        }
    }
}

Where myGridView is an instance of a GridView created in the aspx page. The list users should be a list of whatever class you want to create to show user data, which will determine how your GridView instance will be formatted.

Just to get you to the point where you can see your database query working at all you can instead do the following from your query result (though I definitely recommend implementing the GridView eventually):

System.Text.StringBuilder sb = new System.Text.StringBuilder();
using (SqlDataReader rd = command.ExecuteReader())
{
    if (rd.HasRows)
    {
        while (rd.Read())
        {
            sb.Append(rd[0].ToString());
            sb.Append("<br />");
        }
    }
}
Row1.InnerHtml = sb.ToString();

And you will have to change your Row1 to 

<td id="Row1" style="width: 73px" runat="server">&nbsp;</td>

Upvotes: 1

Chains
Chains

Reputation: 13157

Per the error, you'll need to bring your Row1 variable into scope

TableRow Row1 = new TableRow();
while (rd.Read())
{
   Row1.Items.Add(rd[0].ToString());
   Table1.Rows.Add(Row1);
}

Upvotes: 0

Related Questions