JDBC连接MYSQL,JDBC增删改查 经典 范例
来源：互联网 发布：智通作图软件 编辑：程序博客网 时间：2024/06/05 16:42
一切详情请看代码：绝对经典，注视写的很清楚
package cn.csdn.dao;import java.util.List;import cn.csdn.domain.User;public interface UserDao {boolean insert(User entity);boolean checkUser(String name);public boolean delete(User entity);public boolean update(User entity);User findById(Integer id);List findAll();}package cn.csdn.dao;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import cn.csdn.domain.User;public class UserDaoImpl implements UserDao{/*声明操作数据的对象*/private static Connection conn;private PreparedStatement pstmt;private ResultSet rs;/*静态块*/static{/*准备驱动程序,加载驱动*/try {Class.forName("com.mysql.jdbc.Driver");/*面试必考题*/conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/job?user=root&password=admin&useUnicode=true&characterEncoding=UTF-8");} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}@Overridepublic boolean checkUser(String name) {/*第一步：声明返回变量*/boolean flag=false;/*第二步：获取连接对象 conn *//*第三步：定义sql语句 "select * from user where name='"+name+"'";*/String sql = "select * from user where name=?";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*/int index = 1;pstmt.setString(index++, name);/*第六步:执行查询*/rs = pstmt.executeQuery();/*第七步:判断*/if(rs.next()){flag = true;}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(rs!=null){try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return flag;}@Overridepublic boolean insert(User entity) {/*第一步：声明返回变量*/boolean flag=false;/*第二步：获取连接对象 conn *//*第三步：定义sql语句 ;insert into user(name,sex,age)values('"+entity.getName()+"','"+entity.getSex()+"',"+entity.getAge()+");"*/String sql = "insert into user(name,sex,age)values(?,?,?);";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*/int index = 1;pstmt.setObject(index++, entity.getName());pstmt.setObject(index++, entity.getSex());pstmt.setObject(index++, entity.getAge());/*第六步:执行更新*/int i = pstmt.executeUpdate();/*第七步:判断*/if(i>0){flag = true;}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}/*记得一定要把返回的值，修改成返回的变量*/return flag;}@Overridepublic boolean delete(User entity) {/*第一步：声明返回变量*/boolean flag=false;/*第二步：获取连接对象 conn *//*第三步：定义sql语句 ;insert into user(name,sex,age)values('"+entity.getName()+"','"+entity.getSex()+"',"+entity.getAge()+");"*/String sql = "delete from user where id=?";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*/int index = 1;pstmt.setInt(index++, entity.getId());/*第六步:执行更新*/int i = pstmt.executeUpdate();/*第七步:判断*/if(i>0){flag = true;}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}/*记得一定要把返回的值，修改成返回的变量*/return flag;}public static void main(String[] args) {/*看明白了嘛*/UserDao userDao = new UserDaoImpl();/*boolean flag = userDao.checkUser("redarmy");if(flag){System.out.println("用户名已经被占用了");}else{System.out.println("用户名还没有被使用,你可以使用此用户名");}*//*boolean flag = userDao.insert(new User(null, "红军12", "男", 20));if(flag){System.out.println("注册成功");}else{System.out.println("注册失败");}*//*List users = userDao.findAll();for (int i = 0; i < users.size(); i++) {User entity = (User) users.get(i);System.out.println(entity.getId()+" "+entity.getName());}*///userDao.update(new User(7,"孙悟空","女",10000));User entity = userDao.findById(7); System.out.println(entity.getId()+" "+entity.getName());}@Overridepublic List findAll() {/*第一步:定义返回结果*/List allentities = new ArrayList();/*第二步:获取连接对象*//*第三步：定义sql语句*/String sql ="select * from user";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*//*第六步:执行查询*/rs = pstmt.executeQuery();/*第七步:判断*/while(rs.next()){User entity = new User();entity.setId(rs.getInt("id"));entity.setName(rs.getString("name"));entity.setSex(rs.getString("sex"));entity.setAge(rs.getInt("age"));allentities.add(entity);}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(rs!=null){try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return allentities;}@Overridepublic boolean update(User entity) {/*第一步：声明返回变量*/boolean flag=false;/*第二步：获取连接对象 conn *//*第三步：定义sql语句 ;insert into user(name,sex,age)values('"+entity.getName()+"','"+entity.getSex()+"',"+entity.getAge()+");"*/String sql = "update user set name=?,sex=?,age=? where id=?";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*/int index = 1;pstmt.setObject(index++, entity.getName());pstmt.setObject(index++, entity.getSex());pstmt.setObject(index++, entity.getAge());pstmt.setInt(index++, entity.getId());/*第六步:执行更新*/int i = pstmt.executeUpdate();/*第七步:判断*/if(i>0){flag = true;}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}/*记得一定要把返回的值，修改成返回的变量*/return flag;}@Overridepublic User findById(Integer id) {/*第一步:定义返回结果*/User entity = new User();/*第二步:获取连接对象*//*第三步：定义sql语句*/String sql ="select * from user where id=?";try {/*第四步：根据sql语句创建预处理对象*/pstmt = conn.prepareStatement(sql);/*第五步：为站位符 赋值*/int index = 1;pstmt.setInt(index++, id);/*第六步:执行查询*/rs = pstmt.executeQuery();/*第七步:判断*/if(rs.next()){entity.setId(rs.getInt("id"));entity.setName(rs.getString("name"));entity.setSex(rs.getString("sex"));entity.setAge(rs.getInt("age"));}} catch (SQLException e) {e.printStackTrace();}/*第八步：关闭*/if(rs!=null){try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(pstmt!=null){try {pstmt.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return entity;}}package cn.csdn.domain;import java.io.Serializable;/*业务Bean*/public class User implements Serializable{/** * */private static final long serialVersionUID = 2646300928284173726L;/**递增序列*/private Integer id;/**姓名*/private String name;/*性别*/private String sex;/*年龄*/private Integer age;public User() {super();// TODO Auto-generated constructor stub}public User(Integer id, String name, String sex, Integer age) {super();this.id = id;this.name = name;this.sex = sex;this.age = age;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}}
----------------代码源自于redarmychen
0 0
- JDBC连接MYSQL,JDBC增删改查 经典 范例
- JDBC连接MYSQL,JDBC增删改查 经典 范例
- JDBC连接MYSQL,JDBC增删改查 经典 范例
- JDBC连接Mysql(连接、增删查改)
- JDBC连接MySQL增删改查
- JDBC连接mysql实现增删改查
- MySQL jdbc增删改查
- JDBC连接MySQL数据库实现增删查改
- Java使用JDBC连接MySQL数据库，实现增删改查
- java jdbc连接mysql数据库实现增删改查操作
- jdbc连接mysql数据库 增删改查demo
- jdbc连接mysql数据库和一套增删改查
- Java使用jdbc连接MySql数据库，实现增删改查
- JDBC连接ORACLE 增删改查
- Jdbc 增删改查
- jdbc增删改查
- JDBC 增删改查
- jdbc增删改查
- Vue.js系列之vue-resource（6）
- 在Android里，应该如何在代码中获取attr属性的值
- 数据结构教程（第四版）P85~87//队列的链式存储结构
- BeanFactory中Bean的生命周期
- 92. Reverse Linked List II**
- JDBC连接MYSQL,JDBC增删改查 经典 范例
- centos用yum安装mongodb及 32位linux（centos）下mongoDB的安装
- 人工智能
- Could not find a valid gem 'cocoapods' (>= 0), here is why: Unable to download data from h
- VBA连接Oracle数据库的两种连接字符串的区别：MSDAORA-对象关闭时不允许操作
- MySQL之数据库模型设计-1 第一范式、第二范式、第三范式理解
- nginx(tengine)编译安装启动配置
- 圣墟 > 第一百二十二章 孔雀南飞
- Java 错误: “不兼容的类型: Object无法转换为int”
