Mybatis知识点全总结

<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>x.x.x</version>
</dependency>

<?xml version="1.0" encoding="UTF-8" ?>
<!--这是xml的约束，根标签为configuration-->
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>  
    <!--驼峰命名转换-->
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
  <!--environments里面可以创建很多environment的环境，default指定默认的环境配置（id）-->
    <environments default="dev">
        <!--environment环境配置,不同的环境用不 同的id-->
        <environment id="dev">
            <!--采用jdbc的方式对数据库的事务进行commit/rollback-->
            <transactionManager type="JDBC"/>
            <!--采用连接池的方式管理数据库连接-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/babytun"/>
                <property name="username" value="root"/>
                <property name="password" value="zc20020106"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="mappers/goods.xml"/>
    </mappers>
</configuration>

<?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">

<transactionManager type="MANAGED">
  <property name="closeConnection" value="false"/>
</transactionManager>

package org.haiexijun.entity;

public class Goods {
    private Integer goodId;//商品编码
    private String title;//标题
    private String subTitle;//子标题
    private Float  originalCost;//原始的价格
    private Float currentPrice;//当前的价格
    private Float discount;//折扣率
    private Integer isFreeDelivery;//是否包邮。1包邮，0不包邮
    private Integer categoryId;//分类编号

    public Integer getGoodId() {
        return goodId;
    }

    public void setGoodId(Integer goodId) {
        this.goodId = goodId;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getSubTitle() {
        return subTitle;
    }

    public void setSubTitle(String subTitle) {
        this.subTitle = subTitle;
    }

    public Float getOriginalCost() {
        return originalCost;
    }

    public void setOriginalCost(Float originalCost) {
        this.originalCost = originalCost;
    }

    public Float getCurrentPrice() {
        return currentPrice;
    }

    public void setCurrentPrice(Float currentPrice) {
        this.currentPrice = currentPrice;
    }

    public Float getDiscount() {
        return discount;
    }

    public void setDiscount(Float discount) {
        this.discount = discount;
    }

    public Integer getIsFreeDelivery() {
        return isFreeDelivery;
    }

    public void setIsFreeDelivery(Integer isFreeDelivery) {
        this.isFreeDelivery = isFreeDelivery;
    }

    public Integer getCategoryId() {
        return categoryId;
    }

    public void setCategoryId(Integer categoryId) {
        this.categoryId = categoryId;
    }
}

<?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="goods">
    <!--select语句，id表示select语句的名称,resultType表示返回查询结果为entity对象的结果-->
    <select id="selectAll" resultType="org.haiexijun.entity.Goods">
        select * from t_goods order by goods_id desc limit 10
    </select>
</mapper>

    <mappers>
        <mapper resource="mappers/goods.xml"/>
    </mappers>

         <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

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.haiexijun.entity.Goods;
import org.junit.Test;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

public class MybatisTest {
    @Test
    public void testtestSelectAll() throws IOException {
        //利用Reader加载classpath下的mybatis-config.xml环形配置文件
        Reader reader=Resources.getResourceAsReader("mybatis-config.xml");
        //初始化SqlSessionFactory
        SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);
        SqlSession sqlSession=null;
        try {
            sqlSession=sqlSessionFactory.openSession();
            sqlSession.selectList("goods.selectAll");
            List<Good> goods= sqlSession.selectList("goods.selectAll");
            for (Good g:goods){
                System.out.println(g.getSubTitle());
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            //如果type=”POOLED",代表连接池，close则是将连接回收到连接池中
            //如果type=“UNPOOLED"，代表将连接关闭
            if (sqlSession!=null){
                sqlSession.close();
            }
        }
    }
}

String resource = "org/mybatis/example/mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

package org.haiexijun.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.Reader;

//工具类的方法和属性一般都用static关键字修饰
public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory=null;
    //用于初始化静态对象
    static {
        Reader reader= null;
        try {
            reader = Resources.getResourceAsReader("mybatis-config.xml");
            sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader);
        } catch (IOException e) {
            e.printStackTrace();
            //把异常抛出去，让使用到这个工具类的程序也知道我们这段代码出错了
            //ExceptionInInitializerError是初始化异常
            throw new ExceptionInInitializerError(e);
        }
    }
    //创建一个方法获取SqlSession对象
    public static SqlSession openSession(){
        return sqlSessionFactory.openSession();
    }
    //关闭（回收）SqlSession的连接的方法
    public static void closeSession(SqlSession session){
        if (session !=null){
            session.close();
        }
    }
}

    @Test
    public void testMybatisUtils(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            List<Good> goods= sqlSession.selectList("goods.selectAll");
            for (Good g:goods){
                System.out.println(g.getSubTitle());
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

<settings>
  <setting name="cacheEnabled" value="true"/>
  <setting name="lazyLoadingEnabled" value="true"/>
  <setting name="multipleResultSetsEnabled" value="true"/>
  <setting name="useColumnLabel" value="true"/>
  <setting name="useGeneratedKeys" value="false"/>
  <setting name="autoMappingBehavior" value="PARTIAL"/>
  <setting name="autoMappingUnknownColumnBehavior" value="WARNING"/>
  <setting name="defaultExecutorType" value="SIMPLE"/>
  <setting name="defaultStatementTimeout" value="25"/>
  <setting name="defaultFetchSize" value="100"/>
  <setting name="safeRowBoundsEnabled" value="false"/>
  <setting name="mapUnderscoreToCamelCase" value="false"/>
  <setting name="localCacheScope" value="SESSION"/>
  <setting name="jdbcTypeForNull" value="OTHER"/>
  <setting name="lazyLoadTriggerMethods" value="equals,clone,hashCode,toString"/>
</settings>

    <select id="selectById" parameterType="Integer" resultType="org.haiexijun.entity.Goods">
           select * from t_goods where goods_id = #{value}
    </select>

    @Test
    public void testSelectById(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Good good= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <select id="selectByPriceRange" parameterType="java.util.Map" resultType="org.haiexijun.entity.Goods">
        select * from t_goods where current_price between #{min} and #{max} order by current_price limit 0,#{limit}
    </select>

    @Test
    public void testSelectByPriceRange(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Map param=new HashMap();
            param.put("min",100);
            param.put("max",500);
            param.put("limit",10);
            List<Good> goods= sqlSession.selectList("goods.selectByPriceRange",param);
            for (Good g:goods){
                System.out.println(g.getTitle()+":"+g.getCurrentPrice());
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <select id="selectGoodsMap" resultType="java.util.Map">
        select g.* , c.category_name from t_goods g,t_category c
        where g.category_id = c.category_id
    </select>

    @Test
    public void testSelectGoodsMap(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            List<Map> list= sqlSession.selectList("goods.selectGoodsMap");
            for (Map m:list){
                System.out.println(m);
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <select id="selectGoodsMap" resultType="java.util.LinkedHashMap">
        select g.* , c.category_name from t_goods g,t_category c
        where g.category_id = c.category_id
    </select>

package org.haiexijun.dto;

import org.haiexijun.entity.Goods;

public class GoodsDTO {
    //Goods实体的引用
    private Goods goods=new Goods();
    //其他字段
    private String categoryName;

    public Good getGoods() {
        return goods;
    }

    public void setGoods(Good goods) {
        this.goods = goods;
    }

    public String getCategoryName() {
        return categoryName;
    }

    public void setCategoryName(String categoryName) {
        this.categoryName = categoryName;
    }
}

    <!--结果映射-->
    <resultMap id="rmGoods" type="org.haiexijun.dto.GoodsDTO">
        <!--设置主键字段和属性映射-->
        <id property="goods.goodsID" column="good_id"/>
        <!--设置非主键字段与属性映射-->
        <result property="goods.title" column="title"/>
        <result property="goods.subTitle" column="sub_title"/>
        <result property="goods.originalCost" column="original_cost"/>
        <result property="goods.currentPrice" column="current_price"/>
        <result property="goods.discount" column="discount"/>
        <result property="goods.isFreeDelivery" column="is_free_delivery"/>
        <result property="goods.categoryId" column="category_id"/>
        <!--特殊的DTO的字段,property直接传入字段名-->
        <result property="categoryName" column="category_name"/>
    </resultMap>

    <select id="selectGoodsDTO" resultMap="rmGoods">
        select g.* , c.category_name from t_goods g,t_category c
        where g.category_id = c.category_id
    </select>

    @Test
    public void testSelectGoodsDTO(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            List<GoodsDTO> list= sqlSession.selectList("goods.selectGoodsDTO");
            for (GoodsDTO g:list){
                System.out.println(g.getGoods().getTitle());
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <insert id="insert" parameterType="org.haiexijun.entity.Goods">
        insert into t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery,category_id)
        values(#{title},#{subTitle},#{originalCost},#{currentPrice},#{discount},#{isFreeDelivery},#{categoryId})
    <selectKey resultType="Integer" keyProperty="goodId" order="AFTER">
        select last_insert_id()
    </selectKey>
    </insert>

    @Test
    public void testInsert(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
            Goods goods=new Goods();
            goods.setTitle("测试商品");
            goods.setSubTitle("测试商品的子标题");
            goods.setOriginalCost(200f);
            goods.setCurrentPrice(100f);
            goods.setDiscount(0.5f);
            goods.setIsFreeDelivery(1);
            goods.setCategoryId(43);
            System.out.println(goods.getSubTitle());
            //insert（）方法的返回值代表本次成功插入的记录总数
            int n=session.insert("goods.insert",goods);
            System.out.println(n);
            //提交事务
            session.commit();
        }catch (Exception e){
            //回滚事务
            if (session!=null){
                session.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

    <insert id="insert" parameterType="org.haiexijun.entity.Goods" useGeneratedKeys="true" keyProperty="goodId" keyColumn="goodId">
        insert into t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery,category_id)
        values(#{title},#{subTitle},#{originalCost},#{currentPrice},#{discount},#{isFreeDelivery},#{categoryId})
    </insert>

    <update id="update" parameterType="org.haiexijun.entity.Goods">
        update t_goods 
        set 
        title = #{title},
        sub_title = #{subTitle},
        original_cost = #{originalCost},
        current_price = #{current_price},
        discount = #{discount},
        is_free_delivery = #{isFreeDelivery},
        category_id = #{categoryId}
        where
        goods_id=#{goodId}
    </update>

    @Test
    public void testUpdate(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
            Goods goods = session.selectOne("goods.selectById",2679);
            goods.setTitle("更新的测试商品");
            goods.setSubTitle("更新的测试商品的子标题");
            goods.setOriginalCost(300f);
            goods.setCurrentPrice(150f);
            int n=session.update("goods.update",goods);
            //提交事务
            session.commit();
        }catch (Exception e){
            //回滚事务
            if (session!=null){
                session.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

    <delete id="delete" parameterType="Integer">
        delete
        from t_goods
        where goods_id=#{value};
    </delete>

    @Test
    public void testDelete(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
            session.delete("goods.delete",2683);
            //提交事务
            session.commit();
        }catch (Exception e){
            //回滚事务
            if (session!=null){
                session.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
            <scope>test</scope>
        </dependency>

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
    <appender name="trace" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <patten>%d{HH:mm:ss:SSS} [%thread] %-5level %logger{36} - %msg%n</patten>
        </encoder>
    </appender>
    <root level="trace">
        <appender-ref ref="console"/>
    </root>
</configuration>

    <select id="dynamicSQL" parameterType="java.util.Map" resultType="org.haiexijun.entity.Goods">
        select  * from t_goods
        where
        //添加1=1
        //或包裹where标签
        <where>
        <if test="categoryId != null">
            and category_id =#{categoryId}
        </if>
        <if test="currentPrice != null">
            and current_price &lt; #{currentPrice}
        </if>
        </where>
    </select>

    @Test
    public void testDynamicSQL(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Map param=new HashMap();
            param.put("categoryId",44);
            param.put("currenPrice",500);
            List<Goods> list=sqlSession.selectList("goods.dynamicSQL",param);
            for (Goods g:list){
                System.out.println(g.getTitle());
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    <select id="choose" parameterType="java.util.Map" resultType="org.haiexijun.entity.Goods">
        select * from t_goods
        where
        discount=1
        <choose>
            <when test="categoryId != null">
                and category_id =#{categoryId}
            </when>
        <when test="currentPrice != null">
            and current_price &lt; #{currentPrice}
        </when>
        <otherwise>
            and category_id =30
        </otherwise>
        </choose>
    </select>

    @Test
    public void testLv1Cache(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            Goods good2= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
            System.out.println(good2.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

    @Test
    public void testLv1Cache(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            Goods good2= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
            System.out.println(good2.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }

        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            Goods good2= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
            System.out.println(good2.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }

    }

    @Test
    public void testLv1Cache(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            sqlSession.commit();
            Goods good2= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
            System.out.println(good2.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

<mapper namespace="goods">
    <cache eviction="LRU" flushInterval="600000" size="512" readOnly="true"/>
    ·························
</mapper>

    @Test
    public void testLv1Cache(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }

        try {
            sqlSession=MybatisUtils.openSession();
            Goods good= sqlSession.selectOne("goods.selectById",1603);
            System.out.println(good.getTitle());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }

    }

    <select id="selectById" parameterType="Integer" resultType="org.haiexijun.entity.Goods" useCache="false">
    select * from t_goods where goods_id = #{x}
    </select>

    <insert id="insert" parameterType="org.haiexijun.entity.Goods" useGeneratedKeys="true" keyProperty="goodId" keyColumn="goodId" flushCache="true">
        insert into t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery,category_id)
        values(#{title},#{subTitle},#{originalCost},#{currentPrice},#{discount},#{isFreeDelivery},#{categoryId})
    </insert>

package org.haiexijun.entity;

public class GoodsDetail {
    private Integer gdId;
    private Integer goodsId;
    private String gdPicUrl;
    private Integer gdOrder;

    public Integer getGdId() {
        return gdId;
    }

    public void setGdId(Integer gdId) {
        this.gdId = gdId;
    }

    public Integer getGoodsId() {
        return goodsId;
    }

    public void setGoodsId(Integer goodsId) {
        this.goodsId = goodsId;
    }

    public String getGdPicUrl() {
        return gdPicUrl;
    }

    public void setGdPicUrl(String gdPicUrl) {
        this.gdPicUrl = gdPicUrl;
    }

    public Integer getGdOrder() {
        return gdOrder;
    }

    public void setGdOrder(Integer gdOrder) {
        this.gdOrder = gdOrder;
    }
}

<?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="goodsDetail">
    <select id="selectByGoodsId" parameterType="Integer" resultType="org.haiexijun.entity.GoodsDetail">
        select * from t_goods_detail where goods_id= #{value}
    </select>
</mapper>

package org.haiexijun.entity;

import java.util.List;

public class Goods {
    private Integer goodId;//商品编码
    private String title;//标题
    private String subTitle;//子标题
    private Float  originalCost;//原始的价格
    private Float currentPrice;//当前的价格
    private Float discount;//折扣率
    private Integer isFreeDelivery;//是否包邮。1包邮，0不包邮
    private Integer categoryId;//分类编号
    private List<GoodsDetail> goodsDetails; //商品详情

    public List<GoodsDetail> getGoodsDetails() {
        return goodsDetails;
    }

    public void setGoodsDetails(List<GoodsDetail> goodsDetails) {
        this.goodsDetails = goodsDetails;
    }

    public Integer getGoodId() {
        return goodId;
    }

    public void setGoodId(Integer goodId) {
        this.goodId = goodId;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getSubTitle() {
        return subTitle;
    }

    public void setSubTitle(String subTitle) {
        this.subTitle = subTitle;
    }

    public Float getOriginalCost() {
        return originalCost;
    }

    public void setOriginalCost(Float originalCost) {
        this.originalCost = originalCost;
    }

    public Float getCurrentPrice() {
        return currentPrice;
    }

    public void setCurrentPrice(Float currentPrice) {
        this.currentPrice = currentPrice;
    }

    public Float getDiscount() {
        return discount;
    }

    public void setDiscount(Float discount) {
        this.discount = discount;
    }

    public Integer getIsFreeDelivery() {
        return isFreeDelivery;
    }

    public void setIsFreeDelivery(Integer isFreeDelivery) {
        this.isFreeDelivery = isFreeDelivery;
    }

    public Integer getCategoryId() {
        return categoryId;
    }

    public void setCategoryId(Integer categoryId) {
        this.categoryId = categoryId;
    }
}

    <resultMap id="rmGoods1" type="org.haiexijun.entity.Goods">
        <id column="goods_id" property="goodId"></id>
        <collection property="goodsDetails" select="goodsDetail.selectByGoodsId" column="goods_id"/>
    </resultMap>

    <select id="selectOneToMany" resultMap="rmGoods1">
    select * from t_goods limit 0,1
    </select>

    <mappers>
        <mapper resource="mappers/goods.xml"/>
        <mapper resource="mappers/goods_detail.xml"/>
    </mappers>

    @Test
    public void testSelectOneToMany(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
             Goods goods= session.selectOne("goods.selectOneToMany");
			 List<GoodsDetail> gd=goods.getGoodsDetails();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

package org.haiexijun.entity;

public class GoodsDetail {
    private Integer gdId;
    private Integer goodsId;
    private String gdPicUrl;
    private Integer gdOrder;
    private Goods goods;

    public Goods getGoods() {
        return goods;
    }

    public void setGoods(Goods goods) {
        this.goods = goods;
    }

    public Integer getGdId() {
        return gdId;
    }

    public void setGdId(Integer gdId) {
        this.gdId = gdId;
    }

    public Integer getGoodsId() {
        return goodsId;
    }

    public void setGoodsId(Integer goodsId) {
        this.goodsId = goodsId;
    }

    public String getGdPicUrl() {
        return gdPicUrl;
    }

    public void setGdPicUrl(String gdPicUrl) {
        this.gdPicUrl = gdPicUrl;
    }

    public Integer getGdOrder() {
        return gdOrder;
    }

    public void setGdOrder(Integer gdOrder) {
        this.gdOrder = gdOrder;
    }
}

    <resultMap id="rmGoodsDetail" type="org.haiexijun.entity.GoodsDetail">
        <id column="gd_id" property="gdId"></id>
        <association column="good_id" property="goods" select="goods.selectById" ></association>
    </resultMap>
    <select id="selectManyToOne" resultMap="rmGoodsDetail">
        select * from t_goods_detail limit 0,1
    </select>

   @Test
    public void testSelectManyTOne(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
            GoodsDetail gd= session.selectOne("goodsDetail.selectManyToOne");
            System.out.println(gd);
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.3.0</version>
</dependency>

    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
    </plugins>

    <select id="selectPage" resultType="org.haiexijun.entity.Goods">
        select * from t_goods where current_price &lt; 1000
    </select>

    @Test
    public void testSelectPage(){
        SqlSession session=null;
        try {
            session=MybatisUtils.openSession();
            //开启分页，startPage方法会自动将下一次查询进行分页，第一个参数为第几页的数据，第二个参数为每一页有多少行
            //下面查询第10-20条数据
            PageHelper.startPage(2,10);
            //下面这个查询要注意，以前返回的是一个List集合，但这里返回的是一个配置对象，包含分页数据和分页信息
           Page<Goods> page =(Page) session.selectList("goods.selectPage");
            System.out.println("总页数:"+page.getPages());
            System.out.println("总记录数："+page.getTotal());
            System.out.println("开始行号："+page.getStartRow());
            System.out.println("结束行号："+page.getEndRow());
            System.out.println("当前页码："+page.getPageNum());
            //当前页数据
            List<Goods> data=page.getResult();
            for (Goods g:data){
                System.out.println(g.getTitle());
            }
            System.out.println("");
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

        <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.5</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/c3p0/c3p0 -->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

package org.haiexijun.dataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.ibatis.datasource.unpooled.UnpooledDataSourceFactory;

/**
 * C3P0与Mybatis兼容使用的数据源工厂类
 */
public class C3P0DataSourceFactory extends UnpooledDataSourceFactory {
    public C3P0DataSourceFactory(){
        //让数据源指向对应的连接池
        this.dataSource=new ComboPooledDataSource();
    }

}

            <!--采用连接池的方式管理数据库连接-->
            <dataSource type="org.haiexijun.dataSource.C3P0DataSourceFactory">
                <property name="driverClass" value="com.mysql.cj.jdbc.Driver"/>
                <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/babytun"/>
                <property name="user" value="root"/>
                <property name="password" value="zc20020106"/>
                <property name="initialPoolSize" value="5"/>
                <property name="maxPoolSize" value="20"/>
            </dataSource>

    <insert id="batchInsert" parameterType="java.util.List" useGeneratedKeys="true" keyColumn="goodId" keyProperty="goodId">
        insert into t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery, category_id)
        values
        <!--foreach子标签专门对parameter传入参数中地list集合进行遍历-->
        <!--item是循环中集合的一项数据，index索引为第几次循环。separator为循环分割符-->
        <foreach collection="list" item="item" index="index" separator=",">
            (#{item.title},#{item.subTitle},#{item.originalCost},#{item.currentPrice},#{item.discount},#{item.isFreeDelivery},#{item.categoryId})
        </foreach>
    </insert>

    @Test
    public void testBatchInsert(){
        SqlSession session=null;
        try {
            long startTime=new Date().getTime();
            session=MybatisUtils.openSession();
            List list=new ArrayList();
            for (int i = 0; i < 10000; i++) {
                Goods goods=new Goods();
                goods.setTitle("测试商品");
                goods.setSubTitle("测试商品子标题");
                goods.setOriginalCost(200f);
                goods.setCurrentPrice(100f);
                goods.setDiscount(0.5f);
                goods.setIsFreeDelivery(1);
                goods.setCategoryId(43);
                list.add(goods);
            }
            session.insert("goods.batchInsert",list);
            session.commit();
            long endTime=new Date().getTime();
            System.out.println("执行时间："+(endTime-startTime)+"毫秒");

        }catch (Exception e){
            if (session!=null){
                session.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

    <delete id="batchDelete" parameterType="java.util.List">
        delete from t_goods where goods_id in
        <!--open设置以什么开始，close设置以什么结束-->
        <foreach collection="list" item="item" index="index" open="(" close=")" separator=",">
            #{item}
        </foreach>
    </delete>

    @Test
    public void testBatchDelete(){
        SqlSession session=null;
        try {
            long startTime=new Date().getTime();
            session=MybatisUtils.openSession();
            List list=new ArrayList();
            for (int i = 1929; i < 11929; i++) {
                list.add(i);
            }
            session.delete("goods.batchDelete",list);
            session.commit();
        }catch (Exception e){
            if (session!=null){
                session.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(session);
        }
    }

package org.haiexijun.dao;

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.haiexijun.entity.Goods;

import java.util.List;

public interface GoodsDAO {
    @Select("select * from t_goods where current_price between #{min} and #{max} order by current_price limit 0,#{limit}")
    public List<Goods> selectByPriceRange(@Param("min") Float min,@Param("max") Float max, @Param("limit") Integer limit);
}

	<mappers>
        <mapper class="org.haiexijun.dao.GoodsDAO"/>
    </mappers>

    <mappers>
       <package name="org.haiexijun.dao"/>
   </mappers>

    @Test
    public void testAnnotationSelect(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            GoodsDAO goodsDAO= sqlSession.getMapper(GoodsDAO.class);
             List<Goods> list=goodsDAO.selectByPriceRange(100f,500f,20);
            System.out.println(list.size());
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }

package org.haiexijun.dao;

import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.SelectKey;
import org.haiexijun.entity.Goods;

import java.util.List;

public interface GoodsDAO {

    @Insert("insert into t_goods(title, sub_title, original_cost, current_price, discount, is_free_delivery,category_id)values(#{title},#{subTitle},#{originalCost},#{currentPrice},#{discount},#{isFreeDelivery},#{categoryId})")
    @SelectKey(statement = "select last_insert_id()",before = false,keyProperty = "goodId",resultType =Integer.class)
    public int insert(Goods goods);

}

    @Test
    public void testAnnotationInsert(){
        SqlSession sqlSession=null;
        try {
            sqlSession=MybatisUtils.openSession();
            Goods goods=new Goods();
            goods.setTitle("测试商品");
            goods.setSubTitle("测试商品的子标题");
            goods.setOriginalCost(200f);
            goods.setCurrentPrice(100f);
            goods.setDiscount(0.5f);
            goods.setIsFreeDelivery(1);
            goods.setCategoryId(43);
            GoodsDAO goodsDAO=sqlSession.getMapper(GoodsDAO.class);
            goodsDAO.insert(goods);
            sqlSession.commit();
        }catch (Exception e){
            if (sqlSession!=null){
                sqlSession.rollback();
            }
            e.printStackTrace();
        }finally {
            MybatisUtils.closeSession(sqlSession);
        }
    }