java操作mysql实现增删改查的方法

本文实例讲述了java操作mysql实现增删改查的方法。分享给大家供大家参考，具体如下：

首先，需要把mysql与java连接的jar（mysql-connector-java-5.1.6-bin.jar）包导入工程.

package com.cn.edu;
import java.beans.statement;
import java.sql.connection;
import java.sql.drivermanager;
import java.sql.preparedstatement;
import java.sql.resultset;
import java.sql.sqlexception;
public class helloworld {
  private connection conn = null;
  preparedstatement statement = null;
  // connect to mysql
  void connsql() {
    string url = "jdbc:mysql://localhost:3306/hello?characterencoding=utf-8";
    string username = "root";
    string password = "root"; // 加载驱动程序以连接数据库
    try {
      class.forname("com.mysql.jdbc.driver" );
      conn = drivermanager.getconnection( url,username, password );
      }
    //捕获加载驱动程序异常
     catch ( classnotfoundexception cnfex ) {
       system.err.println(
       "装载 jdbc/odbc 驱动程序失败。" );
       cnfex.printstacktrace();
     }
     //捕获连接数据库异常
     catch ( sqlexception sqlex ) {
       system.err.println( "无法连接数据库" );
       sqlex.printstacktrace();
     }
  }
  // disconnect to mysql
  void deconnsql() {
    try {
      if (conn != null)
        conn.close();
    } catch (exception e) {
      system.out.println("关闭数据库问题 ：");
      e.printstacktrace();
    }
  }
  // execute selection language
  resultset selectsql(string sql) {
    resultset rs = null;
    try {
      statement = conn.preparestatement(sql);
      rs = statement.executequery(sql);
    } catch (sqlexception e) {
      e.printstacktrace();
    }
    return rs;
  }
  // execute insertion language
  boolean insertsql(string sql) {
    try {
      statement = conn.preparestatement(sql);
      statement.executeupdate();
      return true;
    } catch (sqlexception e) {
      system.out.println("插入数据库时出错：");
      e.printstacktrace();
    } catch (exception e) {
      system.out.println("插入时出错：");
      e.printstacktrace();
    }
    return false;
  }
  //execute delete language
  boolean deletesql(string sql) {
    try {
      statement = conn.preparestatement(sql);
      statement.executeupdate();
      return true;
    } catch (sqlexception e) {
      system.out.println("插入数据库时出错：");
      e.printstacktrace();
    } catch (exception e) {
      system.out.println("插入时出错：");
      e.printstacktrace();
    }
    return false;
  }
  //execute update language
  boolean updatesql(string sql) {
    try {
      statement = conn.preparestatement(sql);
      statement.executeupdate();
      return true;
    } catch (sqlexception e) {
      system.out.println("插入数据库时出错：");
      e.printstacktrace();
    } catch (exception e) {
      system.out.println("插入时出错：");
      e.printstacktrace();
    }
    return false;
  }
  // show data in ju_users
  void layoutstyle2(resultset rs) {
    system.out.println("-----------------");
    system.out.println("执行结果如下所示:");
    system.out.println("-----------------");
    system.out.println(" 用户id" + "/t/t" + "淘宝id" + "/t/t" + "用户名"+ "/t/t" + "密码");
    system.out.println("-----------------");
    try {
      while (rs.next()) {
        system.out.println(rs.getint("ju_userid") + "/t/t"
            + rs.getstring("taobaoid") + "/t/t"
            + rs.getstring("ju_username")
             + "/t/t"+ rs.getstring("ju_userpwd"));
      }
    } catch (sqlexception e) {
      system.out.println("显示时数据库出错。");
      e.printstacktrace();
    } catch (exception e) {
      system.out.println("显示出错。");
      e.printstacktrace();
    }
  }
  public static void main(string args[]) {
    helloworld h = new helloworld();
    h.connsql();
    string s = "select * from ju_users";
    string insert = "insert into ju_users(ju_userid,taobaoid,ju_username,ju_userpwd) values("+8329+","+34243+",'mm','789')";
    string update = "update ju_users set ju_userpwd =123 where ju_username= 'mm'";
    string delete = "delete from ju_users where ju_username= 'mm'";
    if (h.insertsql(insert) == true) {
      system.out.println("insert successfully");
      resultset resultset = h.selectsql(s);
      h.layoutstyle2(resultset);
    }
    if (h.updatesql(update) == true) {
      system.out.println("update successfully");
      resultset resultset = h.selectsql(s);
      h.layoutstyle2(resultset);
    }
    if (h.insertsql(delete) == true) {
      system.out.println("delete successfully");
      resultset resultset = h.selectsql(s);
      h.layoutstyle2(resultset);
    }
    h.deconnsql();
  }
}

notice:

1、现在一般用的驱动是com.mysql.jdbc.driver，以前的那个什么org的驱动虽然封装了com.mysql.jdbc.driver，但不好用，过时了。

2、preparestatement(sql)是statement的子类，比statement好用。

3、如果数据库中定义的是int值，那么sql语句中要把int单独提出来。如".....values("+8329+","+34243+",'mm','789')"

更多关于java相关内容感兴趣的读者可查看本站专题：《java数据结构与算法教程》、《java文件与目录操作技巧汇总》、《java操作dom节点技巧总结》和《java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。