How to fix this error exception error ?

[Jahar Heard]

javax.servlet.ServletException: java.sql.SQLException: Before start of result set

   try {
            Class.forName("com.mysql.jdbc.Driver");
            
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/bbtestproject", "snmt", "asdsadagvfd");
                stmt = con.createStatement();
            rs = stmt.executeQuery("SELECT * FROM members");

        
           String nameLogin = rs.getString("user");
         String passWordLogin = rs.getString("pass");
            if (nameInput.equals(nameLogin) && passwordInput.equals(passWordLogin)) {
           out.println("Welcome: ");
            

            }

        } catch (SQLException e) {
            throw new ServletException(e);
        } catch (ClassNotFoundException e) {
            throw new ServletException(e);
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                    out.println("rs problem");
                }
                if (stmt != null) {
                    stmt.close();
                out.println("stmt problem");                }
                if (ps != null) {
                    ps.close();
                out.println("ps problem");
                }
                if (con != null) {
                    con.close();
                }
            } catch (SQLException e) {
            }
        }

this is the code from where it comes . Any ideas ?

[Mohamed Sanaulla]

Vladislav Rashkov wrote:

rs = stmt.executeQuery("SELECT * FROM members");
String nameLogin = rs.getString("user");  
String passWordLogin = rs.getString("pass");  

The ResultSet obtained in the above lines of code would not be pointing to the results obtained from the query. So in order to make it point to the first set of results, you would have to call rs.next()

if(rs.next())
{
  //Do the operation
}

Alternatively, you can alter the query/code as follow:

PreparedStatement statement  = conn.prepareStatement("SELECT * FROM members WHERE user=? AND password=?");
statement.setString(1, nameInput);
statement.setString(2,passwordInput);
ResultSet rs = statement.executeQuery();
if(rs.next())
{
   //Valid user as the details match and the query returns a row.
}

[Jahar Heard]

Thanks!
I found my mistake . I was trying with the wile loop, but seams to be the if operator the right answer. Thanks

[Rene Larsen]

Vladislav Rashkov wrote:Thanks!
I found my mistake . I was trying with the wile loop, but seams to be the if operator the right answer. Thanks

It depends on the number of rows returned - if you use IF then you'll only get the first row, and with WHILE you'll get all rows.

[Jahar Heard]

But with if it works, like I have that two String the name and the password, and when I input them, they are right, no problems, the connection is OK .