products.sql

create table products
(product_id       int auto_increment comment '产品ID'primary key,product_name     varchar(100)   null comment '产品名称',brand            varchar(50)    null comment '品牌',price            decimal(10, 2) null comment '价格',color            varchar(20)    null comment '颜色',storage_capacity varchar(10)    null comment '存储容量',description      text           null comment '描述'
)comment '手机产品表';

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.aistat</groupId><artifactId>mybatis_tech</artifactId><version>1.0-SNAPSHOT</version><!--打包类型--><packaging>jar</packaging><properties><maven.compiler.source>8</maven.compiler.source><maven.compiler.target>8</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><!--所有依赖--><dependencies><!--        MySQL驱动--><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><version>8.0.31</version></dependency><!--        mybatis依赖--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.15</version></dependency><!--测试环境--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.14.8</version><scope>provided</scope></dependency></dependencies></project>

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><settings><setting name="mapUnderscoreToCamelCase" value="true"/><setting name="logImpl" value="STDOUT_LOGGING"/></settings><typeAliases><package name="com.aistart.tech.pojo"/></typeAliases><!--    <typeAliases>-->
<!--        <typeAlias alias="Products" type="com.aistart.tech.pojo.Products"/>--><!--    </typeAliases>--><environments default="development"><environment id="development"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="com.mysql.cj.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/mybatisdb"/><property name="username" value="root"/><property name="password" value="root"/><property name="poolMaximumActiveConnections" value="1"/></dataSource></environment><environment id="testdevelopment"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="com.mysql.cj.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/test"/><property name="username" value="root"/><property name="password" value="root"/></dataSource></environment></environments><mappers><mapper class="com.aistart.tech.mapper.ProductsMapper"/><!--        <mapper resource="com/aistart/tech/mapper/ProductsMapper.xml"></mapper>--></mappers>
</configuration>

ProductsMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.aistart.tech.mapper.ProductsMapper"><sql id="all">product_id, product_name, brand, price, color, storage_capacity, description</sql><resultMap id="selectOneMap" type="com.aistart.tech.dto.PhoneDto"><result column="product_name" property="name"></result><result column="price" property="jg"></result></resultMap><sql id="select">select <include refid="all"></include> from productswhere</sql><!--一个标签中resultmap和resultType只能存在一个用到了resultmap就写resultmap--><select id="selectOneMap" resultMap="selectOneMap"><include refid="select"></include>product_id = 1;</select><select id="selectOneByNameAndPrice" resultType="Products"><include refid="select"></include>product_name = #{productName}andprice > #{price}</select><!--调用    sqlSession.selectOne("com.aistart.tech.mapper.ProductsMapper.selectOne",products)--><!--id作为这个sql的唯一id,调用也是通过它--><insert id="insertOne" parameterType="Products" ><selectKey keyProperty="productId" keyColumn="product_id" resultType="int" order="AFTER">select last_insert_id();</selectKey>insert into products (product_name,color,price)values (#{productName},#{color},#{price})</insert><delete id="deleteOneById">delete from products where product_id = #{askdksad}</delete><update id="updateProductName" parameterType="Products">update products set product_name = #{productName} where product_id = #{productId}</update><select id="selectOneById" parameterType="int" resultType="com.aistart.tech.pojo.Products">/*参数名一个时虽然可以随便写,但是不推荐*/select<include refid="all"></include>from products where product_id = #{productId}/*默认调用了get函数,利用反射,根据get+param()的形式找函数并且执行*/</select><!--JDBC>>>>sql>>>>resultSet>>>获取列并遍历>>>>>>--><select id="selectAll" resultType="com.aistart.tech.pojo.Products">select<include refid="all"></include>from products</select><select id="selectOneBynName" resultType="Products"><include refid="select"></include>product_name = #{name}</select>
</mapper>

Products.java

package com.aistart.tech.pojo;import lombok.*;@Data
@AllArgsConstructor
@NoArgsConstructor
public class Products {private Integer productId;private String productName;private String brand;private Double price;private String color;private String storageCapacity;private String description;}

PhoneDto.java

package com.aistart.tech.dto;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@AllArgsConstructor
@NoArgsConstructor
public class PhoneDto {private String name;private Double jg;
}

ProductsMapper.java

package com.aistart.tech.mapper;import com.aistart.tech.dto.PhoneDto;
import com.aistart.tech.pojo.Products;
import org.apache.ibatis.annotations.*;public interface ProductsMapper {/** 三种传参数方式** 1.直接对象传参* 2.map传参* 3.参数传参*        a.单一传值,不用在乎变量名*        b.多值时,必须指明参数*** */public int insertOne(Products products);public Products selectOneById(int num);/*** todo:*  重要字段:  id(函数名)  传入类型(参数)  返回类型(返回类型)*           sql语句 select标签 @Select   sql语句("")**** 跟之前用mapper语法一致,传参数有以下几个条件* 1.单一值时,随便,自动匹配* 2.多参数时*       a.多个参数@Param("映射的#{}中的`字段")*       b.对象/map,注意映射字段名* @param name(mapper中的paramType)* @return (resultType)*/@Select("select * from products where product_name = #{name}")public Products selectOneByName(String name);//在参数前指定映射
//    @Select("select product_name from products where product_name = #{productName} and price > #{price}")public Products selectOneByNameAndPrice(@Param("productName") String productName,@Param("price") double price);@Results({@Result(property = "name", column = "product_name"),@Result(property = "jg", column = "price")})@Select("select product_name,price from products where product_name = #{productName}")public PhoneDto selectDtoByName(@Param("productName") String productName);/** <select id = "selectDtoByName" paramType ="String" resultType = "PhoneDto" >*       select product_name from products where product_name = #{productName}** </select>* */
}

DButil.java

package com.aistart.tech.utils;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 java.io.IOException;
import java.io.InputStream;public class DButil {private static SqlSessionFactory sqlSessionFactory = null;//测试环境下的工厂private static SqlSessionFactory sqlSessionFactoryTest = null;static {//1.builder  一旦创建了 SqlSessionFactory，就不再需要它了
//        SqlSessionFactoryBuilder sqlSessionFactoryBuilder =//2.获取工厂// 获取资源 org.apache.ibatis.io.Resources;try {InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");//根据资源文件创建工厂sqlSessionFactory  = new SqlSessionFactoryBuilder().build(inputStream);//测试环境的创建工厂
//            sqlSessionFactoryTest  = new SqlSessionFactoryBuilder().build(inputStream,"testdevelopment");} catch (IOException e) {throw new RuntimeException(e);}}public static SqlSession getSqlSession(){//获得Sqlsessionreturn sqlSessionFactory.openSession();}public static void close(SqlSession session){session.close();}}

ProductsMapperTest

package com.aistart.tech.mapper;import com.aistart.tech.pojo.Products;
import com.aistart.tech.utils.DButil;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;import static org.junit.Assert.*;public class ProductsMapperTest {@Testpublic void selectOneById() {//0.获取sqlSessionSqlSession sqlSession = null;try {sqlSession = DButil.getSqlSession();//            Object selectOne = sqlSession.selectOne("com.aistart.tech.mapper.ProductsMapper", 1);// 1.获取mapper//传参是class类型/** 1.mapper和Java中Mapper接口的全限定名高度保持一致* 2.mapper.xml中id和函数名高度保持一致* 3.mapper接口名和Mapper.xml文件名应该高度一致* 4.别查看config中mappers的路径** */ProductsMapper mapper = sqlSession.getMapper(ProductsMapper.class);Products products = mapper.selectOneById(2);System.out.println(products);}catch (Exception e){e.printStackTrace();}finally {sqlSession.close();}}@Testpublic void selectOneByNameAndPrice() {//0.获取sqlSessionSqlSession sqlSession = null;try {sqlSession = DButil.getSqlSession();//            Object selectOne = sqlSession.selectOne("com.aistart.tech.mapper.ProductsMapper", 1);// 1.获取mapper//传参是class类型/** 1.mapper和Java中Mapper接口的全限定名高度保持一致* 2.mapper.xml中id和函数名高度保持一致* 3.mapper接口名和Mapper.xml文件名应该高度一致* 4.别查看config中mappers的路径** */ProductsMapper mapper = sqlSession.getMapper(ProductsMapper.class);Products products = mapper.selectOneByNameAndPrice("小米",0);System.out.println(products);}catch (Exception e){e.printStackTrace();}}@Testpublic void selectOneByName() {SqlSession sqlSession = DButil.getSqlSession();ProductsMapper mapper = sqlSession.getMapper(ProductsMapper.class);System.out.println(mapper.selectOneByName("小米"));sqlSession.close();}@Testpublic void selectDtoByName() {SqlSession sqlSession = DButil.getSqlSession();ProductsMapper mapper = sqlSession.getMapper(ProductsMapper.class);System.out.println(mapper.selectDtoByName("小米"));sqlSession.close();}
}