Question

i am currently using this code for the registration:

value1 = registerEmail.getText().toString();
    value2 = registerPassword.getText().toString();
    value3 = registerName.getText().toString();
    try{
        Class.forName("com.mysql.jdbc.Driver");
        Connection con = DriverManager.getConnection(url, user, pass);
        Statement st = con.createStatement();
        Log.d("Connectc","executing check");
        ResultSet res = st.executeQuery("SELECT * FROM user where email='"+value1+"'");
        while (res.next()) {
            userc = res.getString("email");
        }
            if (value1.equals(userc)) {
                tv.setText("Email already in use!");
            }
            else{
                Log.d("Connectc","registering");
                st.executeUpdate("INSERT INTO user (email, password, name) VALUES('"+value1+"', '"+value2+"', '"+value3+"' )");
                tv.setText("Data is successfully saved." );
                Intent i = new Intent(getApplicationContext(),
                        LoginActivity.class);
                                    startActivity(i);
                finish();
                Log.d("Connectl","pfffffffff");
            }               

Yes, it would be better using json, but i neet to use this… so the code check if the email exist, i also need to check if the username exist, how can i do? I have to add another sql query or i can edit this to check also if the username exist on db?
Thanks.

Answer 1

This will return row if email or username exists so that you can prompt the user that login data already exists:

ResultSet res = st.executeQuery(
"SELECT * FROM user 
where email='"+value1+"' 
OR username='"+ value3+"'");