InvalidArgument=Value of '0' is not valid for 'index' error

Question

Hello I have two comboboxes on my windows form. When loading it I want the second box to display only the values for which one of the fields from the database are the same as the displayed value in the first combobox. I tried with this code: command3.CommandText = Select * from Komintent order by Komintent asc; command2.CommandText = Select * from Dogovor where Komintent=? order by Brdog; //I use this command to fill the second combobox command2.Parameters.AddWithValue(@Komintent comboBox3.Items[0]); and I got this error: InvalidArgument=Value of '0' is not valid for 'index'. Parameter name: index in the bold line above. Could anybody please help me how to display only filtered data in the second combobox? Thank you very much in advance.

Nel · Answer

Now I get error: No value given for one or more required parameters.

Krishna Garad · Answer

try to change the value which you are passing as arguments like bellow com1.Parameters.AddWithValue(@Komint comboBox3.SelectedItem.Text.ToString()); or com1.Parameters.AddWithValue(@Komint comboBox3.SelectedValue.ToString());

Nel · Answer

Thanks Krishna I tried this but got the same error.

Krishna Garad · Answer

you are retriving data in dataset and are trying to execute the nonquery which is not possible modify your code like bellow private void comboBox3_SelectionChangeCommitted(object sender EventArgs e) { DataSet3 _dataset = new DataSet3(); OleDbCommand com1 = new OleDbCommand(); com1.CommandText = Select * from Dogovor where Komint=@Komint order by Brdog; com1.Parameters.AddWithValue(@Komint comboBox3.SelectedItem); OleDbDataAdapter oleDBDataAdapter1 = new OleDbDataAdapter(new OleDbCommand(com1 conn)); try { oleDBDataAdapter1.Fill(_dataset Komint); //here you are making mistake before filling dataset you are trying to bind it to combo first fill the dataset and then bind it. comboBox2.DataSource = _dataset.Tables[Dogovor]; comboBox2.DisplayMember = Brdog; } finally { } textBox1.Focus(); }

Nel · Answer

Thanks Krishna but nothing changed unfortunately:(

Krishna Garad · Answer

just modify your command text like bellow com1.CommandText = Select * from Dogovor where Komint=@Komint order by Brdog; com1.Parameters.AddWithValue(@Komint comboBox3.SelectedItem);

Nel · Answer

Thanks Krishna. I created this code now private void comboBox3_SelectionChangeCommitted(object sender EventArgs e) { DataSet3 _dataset = new DataSet3(); OleDbCommand com1 = new OleDbCommand(); com1.Connection = conn; com1.CommandText = Select * from Dogovor where Komint=? order by Brdog; com1.Parameters.AddWithValue(@Komint comboBox3.SelectedItem); OleDbDataAdapter oleDBDataAdapter1 = new OleDbDataAdapter(new OleDbCommand(com1.CommandText conn)); try { conn.Open(); com1.ExecuteNonQuery(); comboBox2.DataSource = _dataset.Tables[Dogovor]; comboBox2.DisplayMember = Brdog; oleDBDataAdapter1.Fill(_dataset Komint); } finally { conn.Close(); } textBox1.Focus(); } and get the following error on the bold line: Multiple-step OLE DB operation generated errors. Check each OLE DB status value if available. No work was done.

Krishna Garad · Answer

i think so you are binding both of the comboboxes in page_load and for second combo box you are passing the selected record from first combo but when page is loading first combo contains only items no any item is selected in first but still you are passing the selected item of first combo just instead of using like this first load the combo1 and on selected index changed of combo1 you can populate second combo.