How to display a new row without removing the previous rows (c# datagridview)?

Question

ok so I made a datagridview. when I enter the primary key it will display the data. what I want to do next is make it so that when I enter another primary key it will display the next data and the previous data. heres what I got

public void loadDataGrid(string sqlQueryString)
{
OleDbCommand SQLQuery = new OleDbCommand();
DataTable data = null;
dataGridView1.DataSource = null;
SQLQuery.Connection = null;
OleDbDataAdapter dataAdapter = null;

dataGridView1.Columns.Clear();
SQLQuery.CommandText = sqlQueryString;
SQLQuery.Connection = database;
data = new DataTable();
dataAdapter = new OleDbDataAdapter(SQLQuery);
dataAdapter.Fill(data);
dataGridView1.DataSource = data;
dataGridView1.AllowUserToAddRows = false;
dataGridView1.ReadOnly = true;
dataGridView1.Columns[0].Visible = false;
}

currently it just displays the recent data only, it doesnt show the previous ones.. is there a command to do this?

kiran kumar · Answer

hello friendi wrote a sample code for you according to your requirements.i am uploading my project files here.test it and let me know if it satisfies your requirements. PLEASE MARK THE ANSWER IF IT HELPS YOU

kiran kumar · Answer

replace like this Oledbconnection con = new Oledbconnection(your connection string); replace all class related to sqlclient to oledb if it is sqlcommand replace it with oledbcommand if it is sqldatareader -> oledbdatareader sqldataadapter -> oledbdataadapter PLEASE MARK THE ANSWER IF IT HELPS YOU

wsdfg · Answer

nvm got it to work wee thanks kiran. now I want to add some more functionality. this time I want to make so that if I input a cardnum thats already being displayed. it removes the row from the datagridview (not the database just in the datagridview) heres what I got so far private void CheckKeys3(object sender System.Windows.Forms.KeyPressEventArgs e) { if (e.KeyChar == (char)13) { string card = textBox1.Text.ToString(); int cardnum = int.Parse(card); park = park - 1; OleDbConnection con = new OleDbConnection(Provider=Microsoft.Jet.OLEDB.4.0;Data Source=car.mdb); con.Open(); OleDbCommand queryString = new OleDbCommand(SELECT cardnum ownerf ownerl make model year color chassisnumber platenumber controlnumber FROM vehicle WHERE vehicle.cardnum =  + cardnum + con); OleDbDataReader dr = queryString.ExecuteReader(); if (dr.Read()) { DataGridViewRow row = new DataGridViewRow(); this.dataGridView1.Rows.Add(row); dataGridView1.Rows[i].Cells[0].Value = dr[cardnum].ToString(); dataGridView1.Rows[i].Cells[1].Value = dr[ownerf].ToString(); dataGridView1.Rows[i].Cells[2].Value = dr[ownerl].ToString(); dataGridView1.Rows[i].Cells[3].Value = dr[make].ToString(); dataGridView1.Rows[i].Cells[4].Value = dr[model].ToString(); dataGridView1.Rows[i].Cells[5].Value = dr[year].ToString(); dataGridView1.Rows[i].Cells[6].Value = dr[color].ToString(); dataGridView1.Rows[i].Cells[7].Value = dr[chassisnumber].ToString(); dataGridView1.Rows[i].Cells[8].Value = dr[platenumber].ToString(); dataGridView1.Rows[i].Cells[9].Value = dr[controlnumber].ToString(); int k=i; do { k = k - 1; if (k >=0) { string wah = dataGridView1[0 k].Value.ToString(); int weh = int.Parse(wah); if (cardnum == weh) { dataGridView1.Rows.RemoveAt(k); dataGridView1.Rows.RemoveAt(i); } } } while (k >=0); i++; } con.Close(); } the bold text is my attempt. but its messed up. any help pls

wsdfg · Answer

dunno if I fixed the previous error (or its still there) but now I get this error No row can be added to a DataGridView control that does not have columns. Columns must be added first.

wsdfg · Answer

its in form2. and can you explain what I did wrong after. thanks in advance

kiran kumar · Answer

send me your modified code.i will rectify your error

wsdfg · Answer

been grappling with this error ExecuteReader: Connection property has not been initialized.

wsdfg · Answer

havent tried it yet but I'll mark you anyway :) one question: SqlConnection con = new SqlConnection(Data Source=KIRAN\SQLEXPRESS;Initial Catalog=kiran;Integrated Security=True); where do I instance my database. I've only used OleDb before so I dont know how to in your code.

wsdfg · Answer

no the data is already in the database I dont want to store or update or anything. I just want to display the data on the datagridview. private void CheckKeys3(object sender System.Windows.Forms.KeyPressEventArgs e) { if (e.KeyChar == (char)13) { string card = textBox1.Text.ToString(); int cardnum = int.Parse(card); park = park - 1; string queryString = SELECT cardnum ownerf ownerl make model year color chassisnumber platenumber controlnumber FROM vehicle WHERE vehicle.cardnum =  + cardnum + ; loadDataGrid(queryString); if (park > 0) { textBox2.Text = available; } if (park { textBox2.Text = full; } textBox1.Clear(); } } thats for the query string note since I am querying using the primary key. only 1 row of data will be displayed on the datagridview. what I want is to make it so that if I make another query the previous row of data will still be there along with the newly queried row of data. anyway to do this?

Sam Hobbs · Answer

What about the database? Does both the recent data and the previous data get saved in the table or does just the recent data get stored? Probably you are updating the data for a primary key instead of inserting a new row with a new primary key.