How to display sql data in data grid view when a text and id is entered in a text box

Question

How to display sql data in the data grid view when a text is entered in text box.for eg:there is wai wai and britannia in dBase.I want to display all the information of data base in data grid column when product_name or product_id is entered in the Product Name: textbox.I've tried the following code: but its not working:

private void textBox2_KeyDown(object sender, KeyEventArgs e)
{
    if(e.KeyData==Keys.Enter)
    {
        SqlConnection con = new SqlConnection("Data Source=SUMIT;Initial Catalog=Project;Integrated Security=True");
        SqlDataAdapter a = new SqlDataAdapter("select product_Name,product_Id,purchase_Price,discount,beforevat_Price,vat_Rate,actual_Cost,Margin,actual_Sp from Product", con);
        DataTable b = new DataTable();
        a.Fill(b);
        dataGridView1.DataSource = b;
        textBox3.Focus();
    }
}

it displays output like below:

Answer 1

You can actually do it this way

string WhrCond = "";
int n;
if(int.TryParse(textBox2.Text, out n))
{
    WhrCond = "product_Id = " + textBox2.Text.Trim() ;
}
else
{
    WhrCond = "product_Name LIKE '%" + textBox2.Text.Trim() + "%'";
}

if(string.IsNullOrEmpty(textBox2.Text))
{
    WhrCond = "1 = 1";
}
SqlConnection con = new SqlConnection("Data Source=SUMIT;Initial Catalog=Project;Integrated Security=True");
SqlDataAdapter a = new SqlDataAdapter("select product_Name as [Product Name],
                        actual_Cost as [Actual Cp], 
                        Margin, 
                        actual_Sp as [Actual SP], 
                        product_Id as [Product Id], 
                        purchase_Price as [Purchase Price], 
                        discount as [Discount], 
                        beforevat_Price as [Before Vat Price],
                        vat_Rate as [Vat%] from Product WHERE " + WhrCond , con);
DataTable b = new DataTable();
a.Fill(b);
dataGridView1.DataSource = b;
textBox3.Focus();

You shall be removing all the data from DGV created on the design time.

Answer 2

I'm assuming your datagridview have no column set at start here (since we use datasource) try erase them.

 private void textBox2_TextChanged(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection("Data Source=SUMIT;Initial Catalog=Project;Integrated Security=True " + "connection timeout=300");
            conn.Open();

            string query = "Select * from Product where product_Name  like '%"+textBox2.Text+"%'";
            SqlDataAdapter a = new SqlDataAdapter(query,conn);
            DataTable b = new DataTable();
            a.Fill(b);
            dataGridView1.DataSource = b;

        }

PS: if you absolutely want set column at start then don't use DataSource but use foreach loop on datatable b.rows then add the rows to datagridview1

DtataGridView1.Rows.Add(b["Product_Name],..,...)

2-like lei said you can use DataPropertyNametoo