How to show if a entry is in a database?

Question

I am currently making a program where I can delete certain entries in a database. I can do it, but I wanted to add a JOptionPane Screen for when it can or cannot find it (so when the name isn't found it should not be found and display a message saying it can't be found). I tried using a result statement but that doesn't seem to work. If anyone knows how to do it please comment on how to do so!

private void btnDeleteActionPerformed(java.awt.event.ActionEvent evt) {                                          
    ArrayList<Cookbook  > recipes = new ArrayList();
    String name = txtName.getText();
    try {
        String url = "jdbc:derby://localhost:1527/Cookbook";
        Connection conn = DriverManager.getConnection(url);
        String query = "DELETE from RECIPES WHERE NAME = ?";
        PreparedStatement pst = conn.prepareStatement(query);
        pst.setString(1, name);
        pst.executeUpdate();




        JOptionPane.showMessageDialog(null, name + " was sucessfully deleted");
    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, "was not found or could not be deleted");
    }

Answer 1

Quoting the javadoc of executeUpdate():

Returns:

either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing

So:

String url = "jdbc:derby://localhost:1527/Cookbook";
try (Connection conn = DriverManager.getConnection(url)) {
    String query = "DELETE from RECIPES WHERE NAME = ?";
    try (PreparedStatement pst = conn.prepareStatement(query)) {
        pst.setString(1, name);
        int rowCount = pst.executeUpdate();
        if (rowCount == 0) {
            JOptionPane.showMessageDialog(null, "'" + name + "' was not found");
        } else if (rowCount == 1) {
            JOptionPane.showMessageDialog(null, "'" + name + "' was successfully deleted");
        } else { // cannot happen if `NAME` has unique index in the database
            JOptionPane.showMessageDialog(null, rowCount + " recipes named '" + name + "' were deleted");
        }
    }
} catch (Exception e) {
    JOptionPane.showMessageDialog(null, "something went wrong: " + e);
}