1. MySQL自帶庫(kù)test添加表user帅霜、role
角色表role
用戶表user
2. 添加依賴匆背，配置屬性
相關(guān)依賴：百度即可，此處略
application.properties
spring.application.name=clean-exeserver.port=8845server.main.class=com.cdqd.app.main.Applicationeureka.client.serviceUrl.defaultZone=http://192.168.3.231:8765/eureka/,http://192.168.3.232:8765/eureka/logging.config=classpath:logback.xml#測(cè)試數(shù)據(jù)庫(kù)spring.datasource.url=jdbc:mysql://127.0.0.1:3306/testspring.datasource.username=rootspring.datasource.password=passwordspring.datasource.driver-class-name=com.mysql.jdbc.Driver#mybatis&&通用Mappermybatis.type-aliases-package=com.cdqd.app.beanmybatis.mapper-locations=classpath:mapper/*.xml
mapper.mappers=com.cdqd.app.common.TkMapper
mapper.identity=MYSQL
mapper.not-empty=false
server.port為訪問端口身冀，訪問方式為：localhost:[server.port]/[控制器名]
spring.datasource.url后需要添加兩個(gè)屬性钝尸，不然會(huì)發(fā)出警告
3.新建實(shí)體類User，Role搂根，UserRole（省略getter珍促、setter）
user.java
importjava.util.Date;importjavax.persistence.Column;importjavax.persistence.GeneratedValue;importjavax.persistence.GenerationType;importjavax.persistence.Id;importjavax.persistence.Table;@Table(name ="user")publicclassUser{//自增ID屬性@Id@GeneratedValue(strategy = GenerationType.IDENTITY)privateInteger id;//名稱@Column(name ="name")privateString name;//年齡@Column(name ="age")privateInteger age;//身份編號(hào)@Column(name ="card_no")privateInteger cardNo;//生日@Column(name ="birthday")privateDate birthday;//角色id@Column(name ="r_id")privateintrId;}
UserRole.java
importcom.cdqd.app.bean.User;publicclassUserRoleextendsUser{privateint roleId;privateStringroleName;privateint atk;privateint armor;privateint penetrate;}
Role.java省略，修改后貌似不需要此實(shí)體類
4. 通用mapper實(shí)現(xiàn)user表的增刪改查
(1). 寫一個(gè)自己的接口繼承通用mapper剩愧，此接口不能被掃描到
importtk.mybatis.mapper.common.Mapper;importtk.mybatis.mapper.common.MySqlMapper;publicinterfaceTkMapperextendsMapper,MySqlMapper {}
(2). 添加UserMapper繼承之前寫的mapper猪叙，用于自己使用
importcom.cdqd.app.entity.UserRole;importcom.cdqd.app.bean.User;importcom.cdqd.app.common.TkMapper;importjava.util.List;publicinterfaceUserMapperextendsTkMapper{ListgetUserRoleByUserId(intid);}
注：此mapper需要被掃描到
getUserRoleByUserId用于映射多表查詢，使用映射文件操作流程為：
controller調(diào)用service仁卷，service調(diào)用mapper
(3). 編寫controller
SqlTestController.java
importcom.cdqd.app.bean.User;importcom.cdqd.app.entity.UserRole;importcom.cdqd.app.mapper.UserMapper;importcom.cdqd.app.service.UserService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.web.bind.annotation.*;importjavax.annotation.Resource;importjava.text.ParseException;importjava.text.SimpleDateFormat;importjava.util.List;@RestControllerpublicclassSqlTestController{//自動(dòng)注入穴翩，一般放在頂部@AutowiredUserMapper userMapper;@Autowiredprivate UserService userService;//測(cè)試controller用@PostMapping("/hello")? ? publicStringhello(StringyourName) {return"Hello,"+ yourName;? ? }//根據(jù)cardNo查詢一條數(shù)據(jù)//只能用于主鍵查找，不用于主鍵的查找沒試過//Get請(qǐng)求锦积，查找user信息@GetMapping("/select_user_info/{id}")? ? publicObjectsearchOneDataByCardNo(@PathVariableintid) {? ? ? ? User user =newUser();? ? ? ? user.setId(id);List list = userMapper.select(user);returnlist;//return selsetOne.toString();}//根據(jù)id查詢user表和role表@RequestMapping("/select/{id}")? ? publicObjectsearchUserAndRoleById(@PathVariableintid){List listUser =userService.getUserRoleByUserId(id);returnlistUser;? ? }//插入一條數(shù)據(jù)@PostMapping("/insert")? ? publicStringinsertOneDate(@RequestParamStringname,@RequestParamStringage,@RequestParamStringcardNo,@RequestParamStringsDate,@RequestParamintroleId) {try{? ? ? ? ? ? User user =newUser();? ? ? ? ? ? user.setName(name);? ? ? ? ? ? user.setAge(Integer.parseInt(age));? ? ? ? ? ? user.setCardNo(Integer.parseInt(cardNo));? ? ? ? ? ? SimpleDateFormat sdf =newSimpleDateFormat("yyyy-MM-dd");? ? ? ? ? ? user.setBirthday(sdf.parse(sDate));? ? ? ? ? ? user.setrId(roleId);? ? ? ? ? ? userMapper.insertSelective(user);return"插入數(shù)據(jù)成功:"+ user.toString();? ? ? ? }catch(ParseException e) {? ? ? ? ? ? e.printStackTrace();return"ERROR芒帕！";? ? ? ? }? ? }//用姓名刪除數(shù)據(jù)@PostMapping("/deleteByName")? ? publicStringdeleteByName(Stringname) {? ? ? ? User user =newUser();? ? ? ? user.setName(name);? ? ? ? userMapper.delete(user);return"刪除成功";? ? }//按主鍵刪除@PostMapping("/deleteById")? ? publicStringdeleteById(Stringid) {? ? ? ? userMapper.deleteByPrimaryKey(Integer.parseInt(id));return"刪除成功";? ? }//更新數(shù)據(jù)@PostMapping("/updateById")? ? publicStringupdateById(@RequestParamStringid,@RequestParamStringname,@RequestParamintage,@RequestParamintcardNo,@RequestParamStringsDate,@RequestParamintroleId) {try{? ? ? ? ? ? User user =newUser();? ? ? ? ? ? user.setId(Integer.parseInt(id));? ? ? ? ? ? user.setName(name);? ? ? ? ? ? user.setAge(age);? ? ? ? ? ? user.setCardNo(cardNo);? ? ? ? ? ? SimpleDateFormat sdf =newSimpleDateFormat("yyyy-MM-dd");? ? ? ? ? ? user.setBirthday(sdf.parse(sDate));? ? ? ? ? ? user.setrId(roleId);? ? ? ? ? ? userMapper.updateByPrimaryKeySelective(user);return"更新完成:"+ user.toString();? ? ? ? }catch(ParseException e) {? ? ? ? ? ? e.printStackTrace();return"ERROR！";? ? ? ? }? ? }}
第一次邊學(xué)邊用所寫丰介，最好用Json返回?cái)?shù)據(jù)背蟆，傳入?yún)?shù)過多同樣推薦使用Json，而不是String哮幢，List等带膀；
controller里最好不要用try/catch，try/catch在不知道會(huì)出現(xiàn)什么異常時(shí)使用較為適宜橙垢，而在controller中大概了解會(huì)出現(xiàn)那個(gè)類型的異常垛叨；
增刪改時(shí)推薦使用post請(qǐng)求（PostMapping），查詢時(shí)推薦使用get請(qǐng)求（GetMapping）柜某，區(qū)別如下：
GET和POST兩種基本請(qǐng)求方法的區(qū)別（他講的比我講的有趣）
PS：命名不規(guī)范嗽元，不要學(xué)我。
5. 映射文件實(shí)現(xiàn)多表查詢
(1). service
UserService.java
importcom.cdqd.app.entity.UserRole;importjava.util.List;publicinterfaceUserService{ListgetUserRoleByUserId(intid);}
service訪問接口
UserServiceImpl.java
packagecom.cdqd.app.service;importcom.cdqd.app.entity.UserRole;importcom.cdqd.app.mapper.UserMapper;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Service;importjava.util.List;@Servicepublic class UserServiceImpl implements UserService {? @AutowiredUserMapper userMapper;? ? ? ? @Overridepublic List getUserRoleByUserId(int id) {returnuserMapper.getUserRoleByUserId(id);? ? }}
service調(diào)用mapper實(shí)現(xiàn)功能
(2). mapper映射文件
userRoleMapper.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"><!--查詢-->select? ? ? ? u.*,? ? ? ? r.role_id as role_id,? ? ? ? r.role_name as role_name,? ? ? ? r.atk as atk,? ? ? ? r.armor as armor,? ? ? ? r.penetrate as penetrate? ? ? ? from user u,role ru.r_id = r.role_id? ? ? ? ? ? and u.id = #{id,jdbcType=INTEGER}
mapper：namespace填寫所對(duì)應(yīng)的mapper路徑
resultMap：id為唯一主鍵莺琳；column(列) 為數(shù)據(jù)庫(kù)中列名，property(屬性)為Java實(shí)體類中屬性名
select：id的值為對(duì)應(yīng)mapper的對(duì)應(yīng)方法名载慈；parameterType參數(shù)類型惭等；resultMap和上面相結(jié)合操作需要的數(shù)據(jù)
6.程序入口
Application.java
importcom.cdqd.app.common.WebUtils;importorg.springframework.boot.SpringApplication;importorg.springframework.boot.autoconfigure.SpringBootApplication;importorg.springframework.cloud.netflix.eureka.EnableEurekaClient;importorg.springframework.context.annotation.ComponentScan;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.RestController;importtk.mybatis.spring.annotation.MapperScan;importjavax.servlet.http.HttpServletRequest;@SpringBootApplication@EnableEurekaClient@RestController@MapperScan("com.cdqd.app.mapper")@ComponentScan(basePackages="com.cdqd.app")publicclassApplication{publicstaticvoid main(String[] args) {SpringApplication.run(Application.class, args);? ? }}
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