Invalid attempt to call Read when reader is closed.

Question

1.00/5 (1 vote)

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note it is windows appplciation

using csharp.

C#

sql = "select [Fac_Name],[Holiday_Day] from Tb_common_Holidays where FacName = '" + cb_Faculty_Code.Text.ToString().Trim() + "' and Holiday_Day = '" + dt1.DayOfWeek.ToString().Trim() + "' ";
                oledbdr = GFun.ReadAcessSql(sql);
                oledbdr.Read();
                if (oledbdr.HasRows == true)
                //while (oledbdr.Read())
                {
                    DGVCalendar.Rows[row].Cells[1].Style.BackColor = Color.Pink;
                    DGVCalendar.Rows[row].Cells[2].Style.ForeColor = Color.Brown;
                    DGVCalendar.Rows[row].Cells[2].Value = dt1.DayOfWeek.ToString();
                }
                oledbdr.Close();

in my above code when i run shows error as follows;

Invalid attempt to call Read when reader is closed.

what is the problem in my above code/

please help me.

Posted 25-Feb-13 22:41pm

Member 8054539

Updated 25-Feb-13 22:42pm

CHill60

v2

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Comments

temisegdave 26-Feb-13 5:14am

is your reader Still Open?

Is the Code outside the scope of the Reader Declared?

===== Oledbdr.Open()====

Let the code above been between "Open" and

===== Oledbdr.Close()======

[no name] 26-Feb-13 5:18am

it is ms access database.

CHill60 26-Feb-13 5:50am

I've amended my solution for access instead of sql

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temisegdave · Answer 1 · 2013-02-25T22:51:00

Solution 1

is your reader Still Open?

Is the Code outside the scope of the Reader Declared?

===== Oledbdr.Open()====

Let the code above been between "Open" and

===== Oledbdr.Close()======

Posted 25-Feb-13 22:51pm

temisegdave

CHill60 · Answer 2 · 2013-02-25T23:12:00

It's not clear when you open your reader - it depends what oledbdr = GFun.ReadAcessSql(sql); actually achieves.

I would rather do something like this ...
[Edit - amended for MSAccess instead of SQL]

C#

sql = "select [Fac_Name],[Holiday_Day] from Tb_common_Holidays where FacName = @P1 and Holiday_Day = @P2";

//SqlCommand cmd = new SqlCommand();
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = yourConnection;
cmd.CommandType = CommandType.Text;
cmd.CommandText = sql;

// Use parameterised queries - you can google for the many reasons why
//cmd.Parameters.Add("@P1", SqlDbType.VarChar, 1024);
//cmd.Parameters.Add("@P2", SqlDbType.VarChar, 1024);
//cmd.Parameters["@P1"].Value = cb_Faculty_Code.Text.ToString().Trim();
//cmd.Parameters["@P2"].Value = dt1.DayOfWeek.ToString().Trim();

cmd.Parameters["@P1"].AddWithValue("P1", cb_Faculty_Code.Text.ToString().Trim());
cmd.Parameters["@P2"].AddWithValue("P2", dt1.DayOfWeek.ToString().Trim());

//SqlDataReader oledbdr = cmd.ExecuteReader();
OleDbDataReader dr = cmd.ExecuteReader();

oledbdr.Read();
if (oledbdr.HasRows == true)
{
   // Note you are only reading the first row
   DGVCalendar.Rows[row].Cells[1].Style.BackColor = Color.Pink;
   DGVCalendar.Rows[row].Cells[2].Style.ForeColor = Color.Brown;
   DGVCalendar.Rows[row].Cells[2].Value = dt1.DayOfWeek.ToString();
}
oledbdr.Close();