【无标题】动手实践：使用DBUtils实现增删改查

1. 搭建开发环境在数据库建表，插入数据
2. 创建JavaBean

   package cn.itcast.jdbc.javabean;
   
   public class User {
           private int id;
           private String name;
           private String password;
           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 String getPassword() {
   
               return password;
           }
           public void setPassword(String password) {
   
               this.password = password;
           }
   
   }
   

   3.创建C3P0Utils工具类

   package cn.itcast.jdbc.utils;
   import javax.sql.DataSource;
   import com.mchange.v2.c3p0.ComboPooledDataSource;
   public class C3p0Utils {
       private static DataSource ds = null;
       static {
           ComboPooledDataSource  cpds = new ComboPooledDataSource();
           try{
               cpds.setDriverClass("com.mysql.cj.jdbc.Driver");
               cpds.setJdbcUrl("jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8");
               cpds.setUser("root");
               cpds.setPassword("123456");
               cpds.setInitialPoolSize(5);
               cpds.setMaxPoolSize(15);
               ds = cpds;
           }catch (Exception e){
               throw new ExceptionInInitializerError(e);
           }
       }
       public static DataSource getDataSource(){
           return ds;
       }
   
   }
   

   4.创建InsertDao类，完成插入操作

   package cn.itcast.jdbc.dao;
   import java.sql.SQLException;
   import org.apache.commons.dbutils.QueryRunner;
   import cn.itcast.jdbc.javabean.User;
   import cn.itcast.jdbc.utils.C3p0Utils;
   public class InsertDao {
       public static  void main(String[] args)throws SQLException{
               QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
               String sql = "insert into user (id,name,password) values('4','hello1',123456)";
               int num = runner.update(sql);
               if(num>0){
                   System.out.println("添加成功！");
               }else{
                   System.out.println("添加失败！");
               }
       }
   }
   

   5.创建UpdateDao类，完成修改操作

   package cn.itcast.jdbc.dao;
   import cn.itcast.jdbc.javabean.User;
   import cn.itcast.jdbc.utils.C3p0Utils;
   import java.sql.SQLException;
   import org.apache.commons.dbutils.QueryRunner;
   
   public class UpdateDao {
       public static void main(String[] args) throws SQLException {
           QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
   
           // 修改后的 SQL 语句
           String sql = "update user set name='hello2', password='111111' where id=4";
   
           // 打印执行的 SQL 语句，确认是否有误
           System.out.println("Executing SQL: " + sql);
   
           // 执行更新操作
           int num = runner.update(sql);
   
           // 打印影响的行数
           System.out.println("Affected rows: " + num);
   
           if (num > 0) {
               System.out.println("修改成功！");
           } else {
               System.out.println("修改失败！");
           }
       }
   }
   

   6.创建DeleteDao类，完成删除操作

   package cn.itcast.jdbc.dao;
   import cn.itcast.jdbc.utils.C3p0Utils;
   import java.sql.SQLException;
   import org.apache.commons.dbutils.QueryRunner;
   public class DeleteDao {
       public static  void main(String[] args)throws SQLException{
           QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
           String sql = "delete from user where name='hello2'";
           int num = runner.update(sql);
           if(num>0){
               System.out.println("删除成功！");
           }else{
               System.out.println("删除失败！");
           }
       }
   }
   

   7.创建QueryDao类，完成查询操作

   package cn.itcast.jdbc.dao;
   import java.sql.SQLException;
   import org.apache.commons.dbutils.QueryRunner;
   import cn.itcast.jdbc.javabean.User;
   import cn.itcast.jdbc.utils.C3p0Utils;
   import org.apache.commons.dbutils.handlers.BeanHandler;
   public class QueryDao {
       public static  void main(String[] args)throws SQLException {
           QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
           String sql = "select * from user where id=2";
           User user= (User)runner.query(sql,
                   new BeanHandler(User.class));
               System.out.println(user.getId() + "," + user.getName() + ","
                       + user.getPassword());
           }
   
   }
   

   package cn.itcast.jdbc.dao;
   import java.sql.SQLException;
   import org.apache.commons.dbutils.QueryRunner;
   import cn.itcast.jdbc.javabean.User;
   import cn.itcast.jdbc.utils.C3p0Utils;
   import org.apache.commons.dbutils.QueryRunner;
   import org.apache.commons.dbutils.handlers.BeanListHandler;
   import java.util.List;
   public class QueryDao {
       public static  void main(String[] args)throws SQLException {
           QueryRunner runner = new QueryRunner(C3p0Utils.getDataSource());
           String sql = "select * from user ";
           List<User> list = runner.query(sql, new BeanListHandler<>(User.class));
   
           for(User user : list) {
               System.out.println(user.getId() + "," + user.getName() + ","
                       + user.getPassword());
           }
       }
   }