Read Integer values via Reader.(Sql-server)

Question

con.Open();
cmd = new SqlCommand("USE PRODUCTS SELECT BOUGHT FROM " +
                     DropDownList1.SelectedItem.Text +
                     " WHERE ID = @ID", con);
cmd.Parameters.Add("ID", SqlDbType.Int).Value = DropDownList2.SelectedIndex;
int i = cmd.ExecuteReader().GetInt32(0);
con.Close();

I can't read integer values with reader like this. I get runtime error System.InvalidOperationException. What is wrong with my code ? if you can't find the mistake, can you explain how can i read integer values with reader ? By the way this part of code gives the error:

int i = cmd.ExecuteReader().GetInt32(0);

Syed Farjad Zia Zaidi · Accepted Answer · 2014-05-24 22:39:42Z

1

Try this:

int x=0;
using (
SqlConnection connection = new SqlConnection(strCon))
{
    SqlCommand command = new SqlCommand(sql_string, connection);
    connection.Open();
    DataReader reader = command.ExecuteReader();
    if (reader.HasRows)
    {
        while (reader.Read())
        {
            x = reader.GetInt32(0);
        }
    } 

    reader.Close();
}

answered May 24, 2014 at 22:39

Syed Farjad Zia Zaidi

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Comments

user3559349 · Accepted Answer · 2014-05-24 22:38:54Z

0

You need to initialise a reader and then read it

using (SqlDataReader rdr = cmd.ExecuteReader())
{
  while (rdr.Read()) // or just rdr.Read() if you know only one row is returned
  {
    int i = rdr.GetInt32(0);

answered May 24, 2014 at 22:38

user3559349

Comments

user229044 · Accepted Answer · 2014-05-25 05:22:24Z

0

What I have done to make things a lot easier on my end, since I mainly use SQL all over the place, is make some extensions.

eg

public static Int32 GetInt32(this SqlDataReader rdr, string column)
{
     return Convert.ToInt32(rdr[column]);
}

edited May 25, 2014 at 5:22

user229044♦

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answered May 24, 2014 at 23:22

Arco

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