Multiple parameter in Row Filter

Question

I am trying to put a textbox as an Rowfilter under a textchanged event !

The code below is used to GRID to get the appropriate Reg_Number or Customer_Name which is entered in the text box!

wat's the surprising fact is, this code directly takes the 2nd Argument

(i.e)
((DataTable)radGridView1.DataSource).DefaultView.RowFilter = "Reg_Number like '%" + radTextBoxControl1.Text + "%'";

tried to switch the lines, but no matter what i did, it ignores the 1st one and takes the 2nd

i tried to put AND to get both in a single line, bt din't work, plz hel me frnzz!

private void radTextBoxControl1_TextChanged(object sender, EventArgs e)
{
    try
    {
        ((DataTable)radGridView1.DataSource).DefaultView.RowFilter =
            "Customer_Name like '%" + radTextBoxControl1.Text + "%'";
        ((DataTable)radGridView1.DataSource).DefaultView.RowFilter =
            "Reg_Number like '%" + radTextBoxControl1.Text + "%'";
    }
    catch (Exception) { }
}

Answer 1

This is because the second assignment replaces the first one

myDataTable.DefaultView.RowFilter = "firstFilter";
myDataTable.DefaultView.RowFilter = "secondFilter";
// Now RowFilter is "secondFilter"

You must combine the 2 filters with a logical OR to get results fulfilling both conditions:

myDataTable.DefaultView.RowFilter = "firstFilter OR secondFilter";

---

var view = ((DataTable)radGridView1.DataSource).DefaultView;
string escapedText = radTextBoxControl1.Text.Replace("'", "''");
view.RowFilter = "Customer_Name LIKE '%" + escapedText + "%' OR " +
                    "Reg_Number LIKE '%" + escapedText + "%'";

It becomes clearer with String.Format:

view.RowFilter = String.Format("Customer_Name LIKE '%{0}%' OR Reg_Number LIKE '%{0}%'",
                               escapedText);

or, since C# 7.0, with string interpolation:

view.RowFilter =
    $"Customer_Name LIKE '%{escapedText}%' OR Reg_Number LIKE '%{escapedText}%'";

Also, make sure to replace single quotes by two single quotes. This enables the SQL string to contain quotes and prevents SQL-injections:

SELECT * FROM myTable WHERE Name = 'Andy''s Pub';

---

The reason you must combine both conditions with OR, and not AND is, that the user will enter either a customer name or a registration number (we have only one textbox).

Alternatively, you could check, whether the entry is formatted like a registration number or not and apply the appropriate filter. In pseudo code:

if (radTextBoxControl1.Text is formatted as reg_nr) {
    view.RowFilter = "Reg_Number LIKE '%" + escapedText + "%'";
} else {
    view.RowFilter = "Customer_Name LIKE '%" + escapedText + "%'";
}

Answer 2

This should work:

((DataTable)radGridView1.DataSource).DefaultView.RowFilter =
    "Customer_Name like '%" + radTextBoxControl1.Text + "%' AND Reg_Number like '%" + radTextBoxControl1.Text + "%'";