DButil（增，删，改，查）整理

最新推荐文章于 2025-07-08 09:43:59 发布

原创最新推荐文章于 2025-07-08 09:43:59 发布 · 447 阅读

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这篇博客主要介绍了新手如何使用DButil进行数据库的增删改查操作，包括QueryRunner类的使用，如insert、query和update方法，以及ResultSetHandler的BeanHandle和BeanListHandle。文章还详细阐述了实现这一过程的步骤，从创建实体类到配置C3P0数据源，以及编写StuDao接口和测试类。

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新手入门

API关键字：

QueryRunner
insert(String sql,ResultSetHandle,Object… args):添加操作
query(String sql,ResultSetHandle,Object… args):查询操作
update(String sql,Object… args)
ResultSetHandler：把ResultSet转对象
BeanHandle(Class type);
BeanListHandle(Class type);

编写StuDao步骤
1.创建实体类student
2.stuDao接口，并先定义方法
3.创建实现类studentDaoImpl
4.使用BDUtils中的QueryRunner类
5.QueryRunner在实例化的时候需要数据源
6.创建c3p0数据源（c3p0-config.xml）文件放在src

编写实体类

package cn.kgc.demo.day04demo.BDUtils;

import java.util.Date;

public class student {
    private String s_id;
    private String s_name;
    private String s_sex;
    private Date s_birthday;
    private String s_class;

    public String getS_id() {
        return s_id;
    }

    public void setS_id(String s_id) {
        this.s_id = s_id;
    }

    public String getS_name() {
        return s_name;
    }

    public void setS_name(String s_name) {
        this.s_name = s_name;
    }

    public String getS_sex() {
        return s_sex;
    }

    public void setS_sex(String s_sex) {
        this.s_sex = s_sex;
    }

    public Date getS_birthday() {
        return s_birthday;
    }

    public void setS_birthday(Date s_birthday) {
        this.s_birthday = s_birthday;
    }

    public String getS_class() {
        return s_class;
    }

    public void setS_class(String s_class) {
        this.s_class = s_class;
    }

    public student(String s_id, String s_name, String s_sex, Date s_birthday, String s_class) {
        this.s_id = s_id;
        this.s_name = s_name;
        this.s_sex = s_sex;
        this.s_birthday = s_birthday;
        this.s_class = s_class;
    }

    public student() {
    }

    @Override
    public String toString() {
        return s_id+s_name+s_sex+s_birthday;
    }
}

实体类方法接口

package cn.kgc.demo.day04demo.BDUtils;

import java.sql.SQLException;
import java.util.List;

public interface UserDao {
    public List<student> queryStuAll() throws SQLException;

    public void addStu(student stu) throws SQLException;

    public void deleteStu (Integer s_id) throws SQLException;

    public void updateStu(Integer s_id) throws SQLException;

    public void queryStu(student stu);
}

接口实现类

package cn.kgc.demo.day04demo.BDUtils;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import java.sql.SQLException;
import java.util.List;

public class UserDaoImpl implements UserDao {
    private ComboPooledDataSource dataSource=new ComboPooledDataSource();
    private QueryRunner qr=new QueryRunner(dataSource);

    //查所有
    @Override
    public List<student> queryStuAll() throws SQLException {
            String sql="   select * from student   ";
            List<student> studentList=qr.query(sql,new BeanListHandler<student>(student.class));
            return studentList;

    }

    //增
    @Override
    public void addStu(student stu) throws SQLException {
        String sql = " insert into student(s_id,s_name,s_sex,s_birthday,s_class)values(?,?,?,?,?)" ;
        qr.insert(sql,new BeanHandler<student>(student.class),stu.getS_id(),stu.getS_name(),stu.getS_sex(),stu.getS_birthday(),stu.getS_class());
    }

    //删
    @Override
    public void deleteStu(Integer s_id) throws SQLException {
        String sql="   delete from student where s_id=?   ";
        qr.insert(sql,new BeanHandler<student>(student.class),s_id);
    }

    //改
    @Override
    public void updateStu(Integer s_id) throws SQLException{
        String sql="   update student set s_name='张三' where s_id=?   ";
        qr.insert(sql,new BeanHandler<student>(student.class),s_id);
    }

    @Override
    public void queryStu(student stu) {

    }
}

测试类

package cn.kgc.demo.day04demo.BDUtils;

import org.junit.Test;

import java.sql.SQLException;
import java.util.Date;
import java.util.List;

public class testStudent {
    //查
    @Test
    public void stuDao1()throws Exception{
        UserDao U1=new UserDaoImpl();
        List<student> stus=U1.queryStuAll();
        for(student a:stus){
            System.out.println(a.getS_id()+"\t"+a.getS_name()+"\t"+a.getS_sex()+"\t"+a.getS_birthday()+"\t"+a.getS_class());
        }
    }

    //增
    @Test
    public void stuDao2() throws Exception{
        UserDao U2=new UserDaoImpl();
        student stu=new student();
        stu.setS_id("123");
        stu.setS_name("赵云");
        stu.setS_sex("男");
        stu.setS_birthday(new Date(new java.util.Date().getTime()));
        stu.setS_class("99999");
        U2.addStu(stu);
    }

    //删
    @Test
    public void stuDao3() throws Exception{
        UserDao U3=new UserDaoImpl();
        U3.deleteStu(123);
    }

    //改
    @Test
    public void stuDao4() throws Exception{
        UserDao U4=new UserDaoImpl();

        U4.updateStu(103);
    }
}

创建C3P0数据源

<?xml version="1.0" encoding="UTF-8" ?>
<c3p0-config>
    <default-config>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="jdbcUrl">jdbc:mysql://localhost:3306/day09hw?characterEncoding=utf-8</property>
        <property name="user">root</property>
        <property name="password">root</property>
    </default-config>
</c3p0-config>

创建db.properties

driverName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/day09hw
user=root
pwd=root