l 完成品牌數據的增刪改查操作

§ 要完成的功能列表清單：□ 查詢? 查詢所有數據? 查看詳情? 條件查詢□ 添加□ 修改? 修改全部字段? 修改動態字段□ 刪除? 刪除一個? 批量刪除準備環境：§ 數據庫表tb_brand drop table if exists tb_brand;CREATE TABLE tb_brand(-- id主鍵id int PRIMARY KEY auto_increment,-- 品牌名稱brand_name varchar(20),-- 企業名稱company_name varchar(20),-- 排序字段ordered int,-- 描述信息description varchar(100),-- 狀態：0：禁用 1：啟用status int );-- 添加數據 insert into tb_brand (brand_name, company_name, ordered, description, status) values ('三只松鼠', '三只松鼠股份有限公司', 5, '好吃不上火',0), ('華為', '華為技術有限公司', 100, '華為致力于構建萬物互聯的智能世界',1), ('小米', '小米科技有限公司', 50, 'are you ok',1);select * from tb_brand; § 實體類Brand§ 測試用例§ 安裝MybatisX插件□ MybatisX是一款基于IDEA的快速開發插件，為效率而生。□ 主要功能：? XML和接口方法相互跳轉? 根據接口方法生成statrment□ 安裝：

接口：BrandMapper.java

import com.itheima.Pojo.Brand; import org.apache.ibatis.annotations.Param;import java.util.List; import java.util.Map;public interface BrandMapper {/*** 查詢所有* @return*/List<Brand> selectAll();/*** 查看詳情：根據id查詢*/Brand selectById(int id);//使用${}占位符時要加入注解 // Brand selectById(@Param("id") int id);/****查詢-多條件查詢* *參數接收* 1.散裝參數：如果方法有多個參數，需要@Param("SQL參數占位符名稱")* 2.Brand對象參數：對象的屬性名稱要和參數占位符名稱一致* 3.map集合參數：map集合的鍵名稱要和參數占位符名稱保持一致** @param status* @param companyName* @param brandName* @return*///參數包含所有的查詢條件//當存在多個參數時，方法有多個參數，需要@Param注解標注一下，參數需要傳遞給誰/*List<Brand> selectByCondition(@Param("status")int status,@Param("companyName")String companyName,@Param("brandName")String brandName);*///List<Brand> selectByCondition(Brand brand);List<Brand> selectByCondition(Map map);/*** 單條件動態查詢* @param brand* @return*/List<Brand> selectByConditionSingle(Brand brand);/*** 添加*/void add(Brand brand);/*** 修改*/int update(Brand brand);/*** 根據id刪除一行*/int deleteById(int id);/*** 根據id批量刪除*/int deleteByIds(@Param("ids")int[] ids); } BrandMapper.xml配置文件 <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><!--namespace:名稱空間 --> <mapper namespace="com.itheima.mapper.BrandMapper"><!--數據庫表的字段名稱 和 實體類的屬性名稱不一樣，則不能自動封裝*起別名：給不一樣的列名起別名，讓列名和實體類的屬性名一樣*缺點：每次查詢都要定義一次別名*<使用sql片段可以解決>*缺點：不靈活*resultMap：1.定義<resultMap>標簽2.在<select>標簽中，使用resultMap屬性替換resultType--><resultMap id="brandResultMap" type="Brand"><!--id:完成主鍵字段的映射column：表的列名property：實體類的屬性名result:完成一般字段的映射column：表的列名property：實體類的屬性名--><result column="brand_name" property="brandName"/><result column="company_name" property="companyName"/></resultMap><!--查詢所有--><select id="selectAll" resultMap="brandResultMap">select *from tb_brand;</select><!--根據id查看詳情--><!--*參數占位符：1.#{}: 會將其替換成?2.${}: 拼sql，會存在sql注入問題3.使用時機*參數傳遞的時候：#{}*表名或者列名不固定的情況下：${}*參數類型：parameterType可以省略*特殊字符處理：1.轉義字符(&lt;)轉義"<"符號2.CDATA區--><select id="selectById" resultMap="brandResultMap">select *from tb_brand where id = #{id};</select><!--<select id="selectById" resultMap="brandResultMap">select * &#45;&#45; from tb_brand where id &lt; #{id};<![CDATA[<]]></select>--><!--查詢-多條件查詢--><!--<select id="selectByCondition" resultMap="brandResultMap">select *from tb_brandwhere status = #{status}and company_name like #{companyName}and brand_name like #{brandName};</select>--><!--動態條件查詢，動態SQL*if 條件判斷：*test：邏輯表達式*有個問題就是當第一個條件不成立并且后面條件成立時sql語句就變成了where后面加and xxx*解決方案：1.恒等式，在where后面加一個恒等式，并且在第一個條件的執行語句前加and2.<where>替換掉sql中的where關鍵字--><select id="selectByCondition" resultMap="brandResultMap">select *from tb_brand/*where 1 = 1*/<where><if test="status != null">and status = #{status}</if><if test="companyName != null and companyName != ''">and company_name like #{companyName}</if><if test="brandName != null and brandName != ''">and brand_name like #{brandName};</if></where></select><!--單條件動態查詢--><select id="selectByConditionSingle" resultMap="brandResultMap">select *from tb_brandwhere<choose> <!--相當于switch--><when test="status != null">/*相當于case*/status = #{status}</when><when test="companyName != null and companyName != ''">/*相當于case*/company_name like #{companyName}</when><when test="brandName != null and brandName != ''">/*相當于case*/brand_name like #{brandName}</when><otherwise> <!--相當于default-->1=1</otherwise></choose></select><!--添加--><insert id="add" useGeneratedKeys="true" keyProperty="id">insert into tb_brand(brand_name, company_name, ordered, description, status)value (#{brandName}, #{companyName}, #{ordered}, #{description}, #{status});</insert><!--修改--><!--<update id="update">update tb_brandset brand_name = #{brandName},company_name = #{companyName},ordered = #{ordered},description = #{description},status = #{status}where id = #{id};</update>--><!--動態修改--><update id="update">update tb_brand<set><if test="brandName != null and brandName != ''">brand_name = #{brandName},</if><if test="companyName != null and companyName != ''">company_name = #{companyName},</if><if test="ordered != null">ordered = #{ordered},</if><if test="description != null and description != ''">description = #{description},</if><if test="status != null">status = #{status}</if></set>where id = #{id};</update><!--刪除一個--><delete id="deleteById">delete from tb_brand where id = #{id};</delete><!--批量刪除--><delete id="deleteByIds">delete from tb_brand where id in<foreach collection="ids" item="id" separator="," open="(" close=")">#{id}</foreach></delete><!--sql片段--><!--<sql id="brand_column">id, brand_name as brandName, company_name as companyName, ordered, description, status</sql><select id="selectAll" resultType="Brand">select<include refid="brand_column"/>from tb_brand;</select>&lt;!&ndash;statement&ndash;&gt;<select id="selectAll" resultType="Brand">select *from tb_brand;</select>--></mapper> 測試代碼： import com.itheima.Pojo.Brand; import com.itheima.mapper.BrandMapper; 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 java.io.InputStream; import java.util.HashMap; import java.util.List; import java.util.Map;public class MybatisTest {/*** 測試練習：查詢所有數據** @throws Exception*/@Testpublic void testSelectAll() throws Exception {//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession();//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句List<Brand> brands = brandMapper.selectAll();System.out.println(brands);//5.釋放資源sqlSession.close();}/*** 測試練習：查看詳情，根據id查詢** @throws Exception*/@Testpublic void testSelectById() throws Exception {//定義局部變量接收參數int id = 1;//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession();//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句Brand brand = brandMapper.selectById(id);System.out.println(brand);//5.釋放資源sqlSession.close();}/*** 查詢-多條件查詢** @throws Exception*/@Testpublic void testSelectByCondition() throws Exception {//定義局部變量接收參數int status = 1;String companyName = "華為";String brandName = "華為";//處理參數//采用模糊查詢需要對輸入的參數進行處理companyName = "%" + companyName + "%";brandName = "%" + brandName + "%";//封裝對象/*Brand brand = new Brand();brand.setStatus(status);brand.setCompanyName(companyName);brand.setBrandName(brandName);*///創建map集合，將map集合作為參數傳入Map<Object, Object> map = new HashMap<Object, Object>();map.put("status", status); // map.put("companyName", companyName); // map.put("brandName", brandName);//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession();//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句//散裝參數//List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);//Brand對象參數//List<Brand> brands = brandMapper.selectByCondition(brand);//Map集合參數List<Brand> brands = brandMapper.selectByCondition(map);System.out.println(brands);//5.釋放資源sqlSession.close();}/*** 查詢-單條件查詢** @throws Exception*/@Testpublic void testSelectByConditionSingle() throws Exception {//定義局部變量接收參數int status = 1;String companyName = "華為";String brandName = "華為";//處理參數//采用模糊查詢需要對輸入的參數進行處理companyName = "%" + companyName + "%";brandName = "%" + brandName + "%";//封裝對象Brand brand = new Brand();brand.setStatus(status);brand.setCompanyName(companyName);brand.setBrandName(brandName);//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession();//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句//散裝參數//List<Brand> brands = brandMapper.selectByCondition(status, companyName, brandName);//Brand對象參數List<Brand> brands = brandMapper.selectByConditionSingle(brand);System.out.println(brands);//5.釋放資源sqlSession.close();}/*** 添加** @throws Exception*/@Testpublic void testAdd() throws Exception {//定義局部變量接收參數int status = 1;String companyName = "香飄飄食品有限公司";String brandName = "香飄飄";int ordered = 100;String description = "一年銷量繞地球三圈";// //處理參數 // //采用模糊查詢需要對輸入的參數進行處理 // companyName = "%" + companyName + "%"; // brandName = "%" + brandName + "%";//封裝對象Brand brand = new Brand();brand.setBrandName(brandName);brand.setCompanyName(companyName);brand.setOrdered(ordered);brand.setDescription(description);brand.setStatus(status);//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession(true);//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句brandMapper.add(brand);Integer i = brand.getId();System.out.println(i);//提交事務 // sqlSession.commit(true);//5.釋放資源sqlSession.close();}/*** 修改** @throws Exception*/@Testpublic void testUpdate() throws Exception {//定義局部變量接收參數int id = 11;int status = 1;String companyName = "香飄飄食品有限公司";String brandName = "香飄飄";int ordered = 200;String description = "香飄飄超好喝，一年銷量繞地球三圈";// //處理參數 // //采用模糊查詢需要對輸入的參數進行處理 // companyName = "%" + companyName + "%"; // brandName = "%" + brandName + "%";//封裝對象Brand brand = new Brand();brand.setId(id); // brand.setBrandName(brandName); // brand.setCompanyName(companyName);brand.setOrdered(ordered); // brand.setDescription(description); // brand.setStatus(status);//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession(true);//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句int count = brandMapper.update(brand);System.out.println(count);//提交事務 // sqlSession.commit(true);//5.釋放資源sqlSession.close();}/*** 根據id刪除** @throws Exception*/@Testpublic void testDeleteById() throws Exception {//定義局部變量接收參數int id = 11;//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession(true);//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句int count = brandMapper.deleteById(id);System.out.println(count);//提交事務 // sqlSession.commit(true);//5.釋放資源sqlSession.close();}/*** 根據id批量刪除** @throws Exception*/@Testpublic void testDeleteByIds() throws Exception {//定義局部變量接收參數int[] ids = {1, 2};//1.加載mybatis核心配置文件，獲取SqlSessionFactory對象String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);//2.獲取SqlSession對象，用它執行sqlSqlSession sqlSession = sqlSessionFactory.openSession(true);//3.獲取接口代理對象BrandMapper brandMapper = sqlSession.getMapper(BrandMapper.class);//4.執行方法即執行sql語句int count = brandMapper.deleteByIds(ids);System.out.println(count);//提交事務 // sqlSession.commit(true);//5.釋放資源sqlSession.close();} }

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