MyEclipse连接MySQL数据库并进行增删改查操作
实现要求
下载MyEclipse的JDBC驱动包
链接：https://pan.baidu.com/s/17bpXqaieiiXVB9RtM6P0-g
提取码：ahgz
导入JDBC驱动包
用SQLyog创建Pet数据库，并按照要求创建pet表
给表中添加行和列并添加一些数据
实现代码
1、在MyEclipse中创建baseDao层基类
package com.offcn.day03.work;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/*
1.获取连接对象
2.通过反射加载驱动
*/
public class BaseDao {
private Connection conn;
// 3305为端口号，pet为数据库名称，数据库账号和密码需要对应
private String url = "jdbc:mysql://127.0.0.1:3305/pet?useUnicode=true&characterEncoding=utf-8";
private String user = "root";
private String password = "root";
public Connection getConnection(){
try {
Class.forName("com.mysql.jdbc.Driver");
if(conn == null){
conn = DriverManager.getConnection(url, user, password);
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/*
1.增删改，第一个参数传递是sql语句，第二个参数传递object类型数组,里面存放动态占位符
2.获取连接
3.得到需要执行aql语句
4.给占位符赋值
5.执行sql语句
6.输出结果
*/
public int update(String sql,Object[] object){
conn = getConnection();
int num = -1;
PreparedStatement ps = null;
try {
ps = conn.prepareStatement(sql);
if(object != null && object.length > 0){
for(int i = 0;i<object.length;i++){
ps.setObject((i+1),object[i]);
}
}
num = ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}finally{
close(conn,ps,null);
}
return num;
}
/*
1.查，第一个参数传递是sql语句，第二个参数传递object类型数组
2.获取连接
3.得到需要执行aql语句
4.给占位符赋值
5.执行sql语句
6.输出结果
*/
public ResultSet getResultSet(String sql,Object[] object){
conn = getConnection();
PreparedStatement ps = null;
ResultSet rs = null;
try {
ps = conn.prepareStatement(sql);
if(object != null && object.length > 0){
for (int i = 0; i < object.length; i++) {
ps.setObject((i+1),object[i]);
}
}
rs = ps.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}finally{
// 因为还要继续使用，先不断开连接
// close(conn,ps,rs);
}
return rs;
}
/*
1.关闭资源
*/
public void close(Connection conn,PreparedStatement ps,ResultSet rs){
try {
if(conn != null){
conn.close();
}
if(ps != null){
ps.cancel();
}
if(rs != null){
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
2、创建对象实例
将对象属性封装，创建有参及无参构造，重写toStringa方法
package com.offcn.day03.work;
import java.io.Serializable;
public class Pet implements Serializable{
private int id;
private String name;
private int health;
private int love;
private String strain;
public Pet() {
super();
}
public Pet(int id, String name, int health, int love, String strain) {
super();
this.id = id;
this.name = name;
this.health = health;
this.love = love;
this.strain = strain;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getHealth() {
return health;
}
public void setHealth(int health) {
this.health = health;
}
public int getLove() {
return love;
}
public void setLove(int love) {
this.love = love;
}
public String getStrain() {
return strain;
}
public void setStrain(String strain) {
this.strain = strain;
}
@Override
public String toString() {
return "Pet [id=" + id + ", name=" + name + ", health=" + health
+ ", love=" + love + ", strain=" + strain + "]";
}
}
3、创建petDao层接口，让工具类重写里面的方法
package com.offcn.day03.work;
import java.util.List;
public interface PetDao {
//查询全部
List<Pet> selectByAll();
//增加
int addPet(Pet pet);
//修改
int updatePet(Pet pet);
//删除
int deletePet(int i);
//分页查询
List<Pet> selectByLimit(Integer currentPageNo,Integer PageSize);
//模糊查询
List<Pet> selectByLike(String name);
}
4、创建PetDao层接口实现类并继承BaseDao层基类
package com.offcn.day03.work;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class PetDaoImpl extends BaseDao implements PetDao {
//全部查询
public List<Pet> selectByAll() {
//创建集合存储
List<Pet> plist = new ArrayList<Pet> ();
String sql = "select * from pet";
ResultSet rs = super.getResultSet(sql, null);
try {
while(rs.next()){
Pet pet = new Pet();
pet.setId(rs.getInt("id"));
pet.setName(rs.getString("name"));
pet.setHealth(rs.getInt("health"));
pet.setLove(rs.getInt("love"));
pet.setStrain(rs.getString("strain"));
plist.add(pet);
}
} catch (SQLException e) {
e.printStackTrace();
}
return plist;
}
//用户增加
public int addPet(Pet pet){
String sql = "insert into pet(name,health,love,strain) values(?,?,?,?)";
Object[] object = {
pet.getName(),pet.getHealth(),pet.getLove(),pet.getStrain()};
int num = super.update(sql, object);
return num;
}
//修改
public int updatePet(Pet pet) {
String sql = "update pet set name = ?,health = ?,love = ?,strain = ? where id = ? ";
Object[] object = {
pet.getName(),pet.getHealth(),pet.getLove(),pet.getStrain(),pet.getId()};
int num = super.update(sql, object);
return num;
}
//删除
public int deletePet(int i) {
String sql = "delete from pet where id = ?";
Object[] object = {
i};
int num = super.update(sql, object);
return num;
}
//分页查询
public List<Pet> selectByLimit(Integer currentPageNo,Integer PageSize) {
List<Pet> plist = new ArrayList<Pet> ();
String sql = "select * from pet limit ?,?";
Object[] object = {
(currentPageNo-1)*PageSize,PageSize};
ResultSet rs = super.getResultSet(sql, object);
try {
while(rs.next()){
Pet pet = new Pet();
pet.setId(rs.getInt("id"));
pet.setName(rs.getString("name"));
pet.setHealth(rs.getInt("health"));
pet.setLove(rs.getInt("love"));
pet.setStrain(rs.getString("strain"));
plist.add(pet);
}
} catch (SQLException e) {
e.printStackTrace();
}
return plist;
}
//模糊查询
public List<Pet> selectByLike(String name) {
List<Pet> plist = new ArrayList<Pet> ();
String sql = "select * from pet where name like ?";
Object[] object = {
name};
ResultSet rs = super.getResultSet(sql, object);
try {
while(rs.next()){
Pet pet = new Pet();
pet.setId(rs.getInt("id"));
pet.setName(rs.getString("name"));
pet.setHealth(rs.getInt("health"));
pet.setLove(rs.getInt("love"));
pet.setStrain(rs.getString("strain"));
plist.add(pet);
}
} catch (SQLException e) {
e.printStackTrace();
}
return plist;
}
}
5、创建测试类
package com.offcn.day03.work;
import java.util.List;
public class PetTest {
public static void main(String[] args) {
//实例化对象
PetDao petDao = new PetDaoImpl();
//测试增加
Pet pet = new Pet();
pet.setName("可达鸭");
pet.setHealth(80);
pet.setLove(90);
pet.setStrain("大黄鸭");
petDao.addPet(pet);
//测试修改
Pet pet = new Pet();
pet.setName("小黄鸭");
pet.setHealth(80);
pet.setLove(90);
pet.setStrain("黄鸭");
pet.setId(5);
petDao.updatePet(pet);
//测试删除
petDao.deletePet(5);
//测试Limit
List<Pet> LimitList = petDao.selectByLimit(1,3);
System.out.println(limitlist);
//测试模糊查询
List<Pet> likeList = petDao.selectByLike("%花%");
System.out.println(likeList);
}
}
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