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java.sql.SQLException: Before start of result set
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:910)
at com.mysql.jdbc.ResultSet.checkRowPos(ResultSet.java:720)
at com.mysql.jdbc.ResultSet.getStringInternal(ResultSet.java:5624)
at com.mysql.jdbc.ResultSet.getString(ResultSet.java:5544)




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package test;
import java.sql.*;

public class Conn {
  public static void main(String[] args) {
 String username = "root";
 String password = "root";
 String url = "jdbc:mysql://127.0.0.1:3306/mysql";

 try {
  String driver = "com.mysql.jdbc.Driver";
  Class.forName(driver);
  java.sql.Connection cn = DriverManager.getConnection(url, username, password);

   
 } catch (ClassNotFoundException cnfex) {
  System.out.println("×°ÔØJDBC/ODBC Çý¶¯³ÌÐòʧ°Ü");
  cnfex.printStackTrace();
 } catch (SQLException sqlex) {
  System.out.println("ÎÞ·¨Áª½ÓÊý¾Ý¿â");
  sqlex.printStackTrace();
 } catch (Exception ex) {
  System.out.println("NoClassDefException");
  ex.printStackTrac