SSM--MyBatis对数据库进行增删改查

r囧r小猫 2022-02-01 13:27 321阅读 0赞

## 一、先附上项目层级目录： ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pfeGluZG9uZw_size_16_color_FFFFFF_t_70][]

## 二、主配置文件：sqlMapConfig.xml ##

配置mapper时一定要搞清它和你的mapper.xml文件的位置关系

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE configuration
      PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>	
     
      <environments default="development">
        <environment id="development">
        
          <transactionManager type="JDBC"/>
          
          <dataSource type="POOLED">
            <property name="driver" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/skh?characterEncoding=utf-8"/>
            <property name="username" value="root"/>
            <property name="password" value="usbw"/>
          </dataSource>
        </environment>
      </environments>
      <mappers>
       <mapper resource="mapper/UserMapper.xml"/>
      </mappers>
    </configuration>

## 三、UserMapper.xml ##

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
      PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
      "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="UserMapper">
     
     <select id="selectById" parameterType="int" resultType="cn.skh.bean.User">
       select * from qwe where id = #{id} 
     </select>
     <select id="selectUserByName" parameterType="String" resultType="cn.skh.bean.User">
        
    	
    	
    	
         select * from qwe where name like "%"#{name}"%"
         
     </select>
     <insert id="insertUser" parameterType="cn.skh.bean.User">
      
       insert into qwe values(#{id},#{name},#{password},#{sex})
     </insert>
     <update id="updateUser" parameterType="cn.skh.bean.User">
         update qwe set name = #{name} where id = #{id}
     </update>
     <delete id="deleteUserById" parameterType="int">
     delete from qwe where id = #{id}
     </delete>
    </mapper>

## 三、JavaBean以及数据库表结构 ##

package cn.skh.bean;
    /**
     * 需要注意的地方 bean中的属性名称要和数据库中的属性名称相对性
     * 属性和数据库中字段的名称要一样 不能这个是name 那个是username
     * @author SKH
     *
     */
    public class User {
         private int id;
         private String name;
         private String password;
         private String sex;
    	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;
    	}
    	public String getSex() {
    		return sex;
    	}
    	public void setSex(String sex) {
    		this.sex = sex;
    	}
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", username=" + name + ", password=" + password + ", sex=" + sex + "]";
    	}
         
    }

id	int	11	
    name varchar	255	
    password varchar	255	
    sex	varchar	255

## 四、测试类 ##

package cn.skh.test;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.List;
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.junit.Test;
    import cn.skh.bean.User;
    public class HelloMyBatis {
    	//测试入门程序 通过id查询用户
    	  private static void test() throws IOException {
    		  //读取配置文件
    		  String resource = "sqlMapConfig.xml";
    		  InputStream in = Resources.getResourceAsStream(resource);
    		  //建造一个建造工厂的东东
    		  SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
               //通过配置文件建造工厂
    		  SqlSessionFactory ssf = ssfb.build(in);
    		   //通过工厂生产商品
    		  SqlSession session = ssf.openSession();
    		   //使用商品 即操作数据库
    	       //参数1:要操作的sql语句     参数2:sql语句的参数
    	       //UserMapper.selectById . 之前为UserMapper配置文件的命名空间 之后为select的id属性值
    	      User u = session.selectOne("UserMapper.selectById",1);
    	      System.out.println(u);
    	}
    	//模糊查询
    	  private static void test2() throws IOException {
    		  //读取配置文件
    		  String resource = "sqlMapConfig.xml";
    		  InputStream in = Resources.getResourceAsStream(resource);
    		//建造一个建造工厂的东东
    		  SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
            //通过配置文件建造工厂
    		  SqlSessionFactory ssf = ssfb.build(in);
    		 //通过工厂生产商品
    		  SqlSession session = ssf.openSession();
    		  //使用商品 即操作数据库
    		  List<User> us = session.selectList("UserMapper.selectUserByName","逯");
    		  for(User u:us) {
    			  System.out.println(u);
    		  }	 
    	}
    	  private static void test3() throws IOException {
    		  //读取配置文件
    		  String resource = "sqlMapConfig.xml";
    		  InputStream in = Resources.getResourceAsStream(resource);
    		  //建造一个建造工厂的东东
    		  SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
               //通过配置文件建造工厂
    		  SqlSessionFactory ssf = ssfb.build(in);
    		   //通过工厂生产商品
    		  SqlSession session = ssf.openSession();
    		   //使用商品 即操作数据库
    	      User u = new User();
    	      u.setId(7);
    	      u.setName("mlk");
    	      u.setPassword("123456");
    	      u.setSex("女");
    	      session.insert("UserMapper.insertUser", u);
    	      session.commit();//提交事务才会生效    
    	}
    	  private static void test4() throws IOException {
    		  //读取配置文件
    		  String resource = "sqlMapConfig.xml";
    		  InputStream in = Resources.getResourceAsStream(resource);
    		  //建造一个建造工厂的东东
    		  SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
               //通过配置文件建造工厂
    		  SqlSessionFactory ssf = ssfb.build(in);
    		   //通过工厂生产商品
    		  SqlSession session = ssf.openSession();
    		   //使用商品 即操作数据库
    	      User u = new User();
    	      u.setId(0);
    	      u.setName("zxx&SKh");
    	      session.update("UserMapper.updateUser", u);
    	      session.commit();//提交事务才会生效    
    	}
    	  private static void test5() throws IOException {
    		  //读取配置文件
    		  String resource = "sqlMapConfig.xml";
    		  InputStream in = Resources.getResourceAsStream(resource);
    		  //建造一个建造工厂的东东
    		  SqlSessionFactoryBuilder ssfb = new SqlSessionFactoryBuilder();
               //通过配置文件建造工厂
    		  SqlSessionFactory ssf = ssfb.build(in);
    		   //通过工厂生产商品
    		  SqlSession session = ssf.openSession();
    		   //使用商品 即操作数据库
    	      session.delete("UserMapper.deleteUserById", 7);
    	      session.commit();//提交事务才会生效    
    	}
      public static void main(String[] args) throws IOException {
           //test();//查询
    	  //test2();//查询
    	  //test3();//添加
    	  //test4();//修改
    	  //test5();//删除
    	}
    }

## 五、最后附上一日志文件(不一定必须要放在你的项目里) ##

要注意此日志文件要与你的sqlConfig.xml处于同一及目录

# Global logging configuration
    log4j.rootLogger=DEBUG, stdout
    # Console output...
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

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