结果集没当前行

结果集没有当前行
java获取结果集，if(rs!=null)，和while(rs.next())区别

com.microsoft.sqlserver.jdbc.SQLServerException: 结果集没有当前行。st = conn.createStatement();ResultSet rs = st.executeQuery(sql);if(rs!=null) {//rs.next();System.out.println(rs.getRow());System.out.println(rs.getString("name"));    }st = conn.createStatement();ResultSet rs = st.executeQuery(sql);while(rs.next()) {//rs.next();System.out.println(rs.getRow());System.out.println(rs.getString("name"));    }