There is already an open DataReader associated with this Command which must be closed first

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C#

         int st1, st2;
         SqlDataReader rd;
         SqlDataReader rd1;

 private void connection()
        {
            if (cn.State == ConnectionState.Open)
            {
                cn.Close();
            }
            cn.Open();
        }  
private void button2_Click(object sender, EventArgs e)
        {
            connection();

            this.st1 = Convert.ToInt32(txtC.Text);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = cn;
            cmd.CommandText = ("select *  from OrderedFood where coustomerId=@CoustomerId");
            cmd.Parameters.AddWithValue("@CoustomerId", this.st1);
            rd = cmd.ExecuteReader();

           while (rd.Read())
            {
                this.st2 = Convert.ToInt32(rd.GetValue(2).ToString());
                MessageBox.Show(st2.ToString());

                 SqlCommand cmd1 = new SqlCommand();
                cmd1.Connection = cn;
                cmd1.CommandText = ("select [name] from Food where id=@FoodId");
                cmd1.Parameters.AddWithValue("@FoodID", this.st2);
                rd1 = cmd1.ExecuteReader();
                if (rd1.Read())
                {
                    string z;
                    z = rd1.GetValue(0).ToString();
                    for (int i = 0; i <= (checkedListBox1.Items.Count - 1); i++)
                    {
                        checkedListBox1.SetItemChecked(i, false); 
                        string x = checkedListBox1.Items[i].ToString();
                        if (z == x)
                        {
                            checkedListBox1.SetItemChecked(i, true); 
                     

                        }

                    }
                }

            }
         }

Now this shows an error"There is already an open DataReader associated with this Command which must be closed first.".
But if is close data reader i can not be able to get data as while (rd.Read())
reader dose not complete retrive data. So what should i do?

Posted 9-Sep-11 0:17am

Md.Arifur Rahman Paragh

Updated 9-Sep-11 10:10am

v4

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Comments

Herman<T>.Instance 9-Sep-11 6:45am

I miss the rd1.Close(); in your code.
so when rd goes to the next line in the reader the rd1 is still open.
After while (rd.Reed()) { } don't forget to close rd too!

Pravin Patil, Mumbai 9-Sep-11 6:57am

100% correct answer....

Md.Arifur Rahman Paragh 9-Sep-11 16:15pm

Thanks but I tried that then it tells error "Reader already closed". But I found a solution that i made two separate connection for the two reader. then it worked.

2 solutions

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

DanHodgson88 · Answer 1 · 2011-09-09T00:43:00

you haven't closed yo if statement mate if(Rd1.read()).

This should actually be a while statement while rd1 is reading do this when there is no more data to read stop:

rd1 = cmd1.ExecuteReader();
                while (rd1.Read())
                {
                    string z;
                    z = rd1.GetValue(0).ToString();
                    for (int i = 0; i <= (checkedListBox1.Items.Count - 1); i++)
                    {
                        checkedListBox1.SetItemChecked(i, false); 
                        string x = checkedListBox1.Items[i].ToString();
                        if (z == x)
                        {
                            checkedListBox1.SetItemChecked(i, true); 
                     
 
                        }
                 }

try something like that

Md.Arifur Rahman Paragh · Answer 2 · 2013-07-30T09:19:00

Solution 2

I found a solution .I made two separate connection for the two reader. then it worked.

Posted 30-Jul-13 9:19am

Md.Arifur Rahman Paragh

Comments

CHill60 31-Jul-13 14:12pm

Why come back nearly 2 years later and post another solution that is the same as the comment you posted in 2011??

There is already an open DataReader associated with this Command which must be closed first

2 solutions

Solution 1

Solution 2

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There is already an open DataReader associated with this Command which must be closed first

2 solutions

Solution 1

Solution 2

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