MyBatis初级实战之二：增删改查
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https://github.com/zq2599/blog_demos
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本文是《MyBatis初级实战》系列的第二篇，通过前文我们知道了如何在SpringBoot中集成MyBatis，本篇就一起来练习基本功：增删改查；
本篇概览
本篇要练习的内容如下：
- 单表的增删改查
- 批量新增
- 联表查询
全文由以下部分组成：
- 新建工程
- 增加启动类
- 增加swagger的配置类，工程包含了swagger，以便稍后在浏览器上验证
- 增加配置文件
- 增加实体类
- 增加mapper配置文件
- 增加mapper接口
- 增加service，调用mapper接口
- 增加controller，调用service服务
- 编写单元测试用例
- 验证
源码下载
- 如果您不想编码，可以在GitHub下载所有源码，地址和链接信息如下表所示(https://github.com/zq2599/blog_demos)：
| 名称 | 链接 | 备注 |
|---|---|---|
| 项目主页 | https://github.com/zq2599/blog_demos | 该项目在GitHub上的主页 |
| git仓库地址(https) | https://github.com/zq2599/blog_demos.git | 该项目源码的仓库地址，https协议 |
| git仓库地址(ssh) | [email protected]:zq2599/blog_demos.git | 该项目源码的仓库地址，ssh协议 |
- 这个git项目中有多个文件夹，本章的应用在mybatis文件夹下，如下图红框所示：
开发
- 本文的实战使用的数据库和表结构与前文《MyBatis初级实战之一：Spring Boot集成》一模一样；
- 前文《MyBatis初级实战之一：Spring Boot集成》新建了父工程mybatis，本文继续在此工程中新增子工程，名为curd，整个子工程文件结构如下：
- 修改父工程mybatis的pom.xml，在dependencyManagement节点下新增两个dependency节点，如下所示，这么做是为了统一管理依赖库的版本：
<dependency>
<groupId>io.springfoxgroupId>
<artifactId>springfox-swagger-uiartifactId>
<version>2.5.0version>
dependency>
<dependency>
<groupId>com.google.code.gsongroupId>
<artifactId>gsonartifactId>
<version>2.8.6version>
dependency>
- 名为curd子工程，其pom.xml内容如下：
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<parent>
<groupId>com.bolingcavalrygroupId>
<artifactId>mybatisartifactId>
<version>1.0-SNAPSHOTversion>
<relativePath>../pom.xmlrelativePath>
parent>
<groupId>com.bolingcavalrygroupId>
<artifactId>curdartifactId>
<version>0.0.1-SNAPSHOTversion>
<name>curdname>
<description>Demo project for Mybatis CURD in Spring Bootdescription>
<properties>
<java.version>1.8java.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<scope>runtimescope>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
<exclusions>
<exclusion>
<groupId>org.junit.vintagegroupId>
<artifactId>junit-vintage-engineartifactId>
exclusion>
exclusions>
dependency>
<dependency>
<groupId>io.springfoxgroupId>
<artifactId>springfox-swagger2artifactId>
dependency>
<dependency>
<groupId>io.springfoxgroupId>
<artifactId>springfox-swagger-uiartifactId>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<scope>testscope>
dependency>
<dependency>
<groupId>com.google.code.gsongroupId>
<artifactId>gsonartifactId>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
plugin>
plugins>
build>
project>
- 增加启动类，注意要用MapperScan注释来指定mapper接口代码的包路径：
package com.bolingcavalry.curd;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.bolingcavalry.curd.mapper")
public class CurdApplication {
public static void main(String[] args) {
SpringApplication.run(CurdApplication.class, args);
}
}
- 本次实战用到了swagger，这样可以很方便的通过浏览器向各个controller接口发送请求，以下是配置类：
package com.bolingcavalry.curd;
import springfox.documentation.service.Contact;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Tag;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Configuration
@EnableSwagger2
public class SwaggerConfig {
@Bean
public Docket createRestApi() {
return new Docket(DocumentationType.SWAGGER_2)
.apiInfo(apiInfo())
.tags(new Tag("UserController", "用户服务"), new Tag("LogController", "日志服务"))
.select()
// 当前包路径
.apis(RequestHandlerSelectors.basePackage("com.bolingcavalry.curd.controller"))
.paths(PathSelectors.any())
.build();
}
//构建 api文档的详细信息函数,注意这里的注解引用的是哪个
private ApiInfo apiInfo() {
return new ApiInfoBuilder()
//页面标题
.title("MyBatis CURD操作")
//创建人
.contact(new Contact("程序员欣宸", "https://github.com/zq2599/blog_demos", "[email protected]"))
//版本号
.version("1.0")
//描述
.description("API 描述")
.build();
}
}
- application.yml内容如下：
server:
port: 8080
spring:
# 数据源
datasource:
username: root
password: 123456
url: jdbc:mysql://192.168.50.43:3306/mybatis?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
driver-class-name: com.mysql.cj.jdbc.Driver
# mybatis配置
mybatis:
# 配置文件所在位置
config-location: classpath:mybatis-config.xml
# 映射文件所在位置
mapper-locations: classpath:mappers/*Mapper.xml
# 日志配置
logging:
level:
root: INFO
com:
bolingcavalry:
curd:
mapper: debug
- 增加user表的实体类User.java，里面带有swagger的注解，方便在swagger页面展示：
package com.bolingcavalry.curd.entity;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
@ApiModel(description = "用户实体类")
public class User {
@ApiModelProperty(value = "用户ID")
private Integer id;
@ApiModelProperty(value = "用户名", required = true)
private String name;
@ApiModelProperty(value = "用户地址", required = false)
private Integer age;
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", age=" + age +
'}';
}
// 省去get和set方法，请您自行补齐
}
- 增加log表的实体类Log.java，里面带有swagger的注解，方便在swagger页面展示：
package com.bolingcavalry.curd.entity;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import java.sql.Date;
/**
* @Description: 实体类
* @author: willzhao E-mail: [email protected]
* @date: 2020/8/4 8:24
*/
@ApiModel(description = "日志实体类")
public class Log {
@ApiModelProperty(value = "日志ID")
private Integer id;
@ApiModelProperty(value = "用户ID")
private Integer userId;
@ApiModelProperty(value = "日志内容")
private String action;
@ApiModelProperty(value = "创建时间")
private Date createTime;
@Override
public String toString() {
return "Log{" +
"id=" + id +
", userId=" + userId +
", action='" + action + '\'' +
", createTime=" + createTime +
'}';
}
// 省去get和set方法，请您自行补齐
}
- 为联表查询的结果准备一个bean，名为LogExtend.java，继承自Log.java，自己只有个userName字段，对应联表查询user表的name字段：
package com.bolingcavalry.curd.entity;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
@ApiModel(description = "日志实体类(含用户表的字段)")
public class LogExtend extends Log {
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
@ApiModelProperty(value = "用户名")
private String userName;
@Override
public String toString() {
return "LogExtend{" +
"id=" + getId() +
", userId=" + getUserId() +
", userName='" + getUserName() + '\'' +
", action='" + getAction() + '\'' +
", createTime=" + getCreateTime() +
'}';
}
}
- 增加user表的mapper映射文件，可见都是些很简单sql，要注意的是批量新增的节点，这里面用到了foreach语法，可以通过集合动态生成sql：
<mapper namespace="com.bolingcavalry.curd.mapper.UserMapper">
<select id="sel" parameterType="int" resultType="user">
select * from user where id = #{id}
select>
<insert id="insertWithFields" useGeneratedKeys="true" keyProperty="id">
insert into user (id, name, age) values (#{id}, #{name}, #{age})
insert>
<insert id="insertBatch" useGeneratedKeys="true" keyProperty="id">
insert into user (id, name, age)
values
<foreach collection="users" item="user" separator=",">
(#{user.id}, #{user.name}, #{user.age})
foreach>
insert>
<select id="findByName" parameterType="String" resultType="user">
select id, name, age from user where name like concat('%', #{name}, '%')
select>
<delete id="delete">
delete from user where id= #{id}
delete>
<delete id="clearAll">
delete from user
delete>
<update id="update">
update user set name = #{name}, age = #{age} where id = #{id}
update>
<select id="totalCount" resultType="java.lang.Integer">
select count(*) from user
select>
mapper>
- 增加log表的mapper映射文件，如下所示，请关注联表操作selExtend，其结果是logExtendResultMap：
<mapper namespace="com.bolingcavalry.curd.mapper.LogMapper">
<resultMap id="logExtendResultMap" type="logExtend">
<id property="id" column="id"/>
<result column="user_id" jdbcType="INTEGER" property="userId"/>
<result column="action" jdbcType="VARCHAR" property="action"/>
<result column="create_time" jdbcType="TIMESTAMP" property="createTime"/>
<result column="user_name" jdbcType="TIMESTAMP" property="userName"/>
resultMap>
<insert id="insertWithFields" useGeneratedKeys="true" keyProperty="id" parameterType="log">
insert into log (id, user_id, action, create_time) values (#{id}, #{userId}, #{action}, #{createTime})
insert>
<select id="selExtend" parameterType="int" resultMap="logExtendResultMap">
select l.id as id,
l.user_id as user_id,
l.action as action,
l.create_time as create_time,
u.name as user_name
from log as l
left join user as u
on l.user_id = u.id
where l.id = #{id}
select>
mapper>
- 增加用户表的mapper接口类UserMapper.java ，对应着映射文件中的sql节点的id：
package com.bolingcavalry.curd.mapper;
import com.bolingcavalry.curd.entity.LogExtend;
import com.bolingcavalry.curd.entity.User;
import org.springframework.stereotype.Repository;
import java.util.List;
@Repository
public interface UserMapper {
User sel(int id);
int insertWithFields(User user);
int insertBatch(List<User> users);
int clearAll();
List<User> findByName(String name);
int update(User user);
int delete(int id);
int totalCount();
LogExtend selExtend(int id);
}
- 增加日志表的mapper接口类LogMapper.java，对应着映射文件中的sql节点的id：
package com.bolingcavalry.curd.mapper;
import com.bolingcavalry.curd.entity.Log;
import com.bolingcavalry.curd.entity.LogExtend;
import org.springframework.stereotype.Repository;
@Repository
public interface LogMapper {
Log sel(int id);
LogExtend selExtend(int id);
int insertWithFields(Log log);
}
- mapper接口完成后就是service层，先写user表的service，如下所示，可见都是对mapper接口的调用：
package com.bolingcavalry.curd.service;
import com.bolingcavalry.curd.entity.User;
import com.bolingcavalry.curd.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
@Autowired
UserMapper userMapper;
public User sel(int id) {
return userMapper.sel(id);
}
public User insertWithFields(User user) {
userMapper.insertWithFields(user);
return user;
}
public List<User> insertBatch(List<User> users) {
userMapper.insertBatch(users);
return users;
}
public int clearAll() {
return userMapper.clearAll();
}
public List<User> findByName(String name) {
return userMapper.findByName(name);
}
public int update(User user) {
return userMapper.update(user);
}
public int delete(int id) {
return userMapper.delete(id);
}
public int totalCount() {
return userMapper.totalCount();
}
}
- 还有log表的service：
package com.bolingcavalry.curd.service;
import com.bolingcavalry.curd.entity.Log;
import com.bolingcavalry.curd.entity.LogExtend;
import com.bolingcavalry.curd.entity.User;
import com.bolingcavalry.curd.mapper.LogMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class LogService {
@Autowired
LogMapper logMapper;
public Log sel(int id){
return logMapper.sel(id);
}
public LogExtend selExtend(int id) {
return logMapper.selExtend(id);
}
public Log insertWithFields(Log log) {
logMapper.insertWithFields(log);
return log;
}
}
- 最后是controller层了，由于使用了swagger，导致controller相对上一篇略微复杂（多了些注解）：
package com.bolingcavalry.curd.controller;
import com.bolingcavalry.curd.entity.User;
import com.bolingcavalry.curd.service.UserService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.ArrayList;
import java.util.List;
@RestController
@RequestMapping("/user")
@Api(tags = {"UserController"})
public class UserController {
@Autowired
private UserService userService;
@ApiOperation(value = "新增user记录", notes="新增user记录")
@RequestMapping(value = "/insertwithfields",method = RequestMethod.PUT)
public User create(@RequestBody User user) {
return userService.insertWithFields(user);
}
@ApiOperation(value = "批量新增user记录", notes="批量新增user记录")
@RequestMapping(value = "/insertbatch", method = RequestMethod.PUT)
public List<User> insertBatch(@RequestBody List<User> users) {
return userService.insertBatch(users);
}
@ApiOperation(value = "删除指定ID的user记录", notes="删除指定ID的user记录")
@ApiImplicitParam(name = "id", value = "用户ID", paramType = "path", required = true, dataType = "Integer")
@RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
public int delete(@PathVariable int id){
return userService.delete(id);
}
@ApiOperation(value = "删除user表所有数据", notes="删除user表所有数据")
@RequestMapping(value = "/clearall", method = RequestMethod.DELETE)
public int clearAll(){
return userService.clearAll();
}
@ApiOperation(value = "根据ID修改user记录", notes="根据ID修改user记录")
@RequestMapping(value = "/update", method = RequestMethod.POST)
public int update(@RequestBody User user){
return userService.update(user);
}
@ApiOperation(value = "根据名称模糊查找所有user记录", notes="根据名称模糊查找所有user记录")
@ApiImplicitParam(name = "name", value = "用户名", paramType = "path", required = true, dataType = "String")
@RequestMapping(value = "/findbyname/{name}", method = RequestMethod.GET)
public List<User> findByName(@PathVariable("name") String name){
return userService.findByName(name);
}
@ApiOperation(value = "根据ID查找user记录", notes="根据ID查找user记录")
@ApiImplicitParam(name = "id", value = "用户ID", paramType = "path", required = true, dataType = "Integer")
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
public User GetUser(@PathVariable int id){
return userService.sel(id);
}
@ApiOperation(value = "获取总数", notes="获取总数")
@RequestMapping(value = "/totalcount", method = RequestMethod.GET)
public int totalcount(){
return userService.totalCount();
}
}
- log的controller如下：
package com.bolingcavalry.curd.controller;
import com.bolingcavalry.curd.entity.Log;
import com.bolingcavalry.curd.entity.LogExtend;
import com.bolingcavalry.curd.service.LogService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("/log")
@Api(tags = {"LogController"})
public class LogController {
@Autowired
private LogService logService;
@ApiOperation(value = "根据ID查找日志记录", notes="根据ID查找日志记录")
@ApiImplicitParam(name = "id", value = "日志ID", paramType = "path", required = true, dataType = "Integer")
@RequestMapping(value = "/{id}", method = RequestMethod.GET)
public LogExtend logExtend(@PathVariable int id){
return logService.selExtend(id);
}
@ApiOperation(value = "新增日志记录", notes="新增日志记录")
@RequestMapping(value = "/insertwithfields",method = RequestMethod.PUT)
public Log create(@RequestBody Log log) {
return logService.insertWithFields(log);
}
}
- 最后是一段单元测试的代码，咱们试试通过junit进行自测，如下所示，可见一共测试了三个controller接口：先新增，再查找，最后删除，要注意的是MockMvc的用法，以及jsonPath方法的用法，还有就是通过Order注解控制执行顺序（一定要添加TestMethodOrder注解，否则Order注解不生效）：
package com.bolingcavalry.curd.controller;
import com.bolingcavalry.curd.entity.User;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonParser;
import org.junit.Ignore;
import org.junit.jupiter.api.*;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import java.util.List;
import java.util.UUID;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.core.IsEqual.equalTo;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
class UserControllerTest {
@Autowired
private MockMvc mvc;
// user表的name字段，这里为了保证测试时新增和删除的记录是同一条，用UUID作为用户名
static String testName;
@BeforeAll
static void init() {
testName = UUID.randomUUID().toString().replaceAll("-","");;
}
@Test
@Order(1)
void insertWithFields() throws Exception {
String jsonStr = "{\"name\": \"" + testName + "\", \"age\": 10}";
mvc.perform(
MockMvcRequestBuilders.put("/user/insertwithfields")
.contentType(MediaType.APPLICATION_JSON)
.content(jsonStr)
.accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$.name", is(testName)))
.andDo(print())
.andReturn()
.getResponse()
.getContentAsString();
}
@Test
@Order(2)
void findByName() throws Exception {
mvc.perform(MockMvcRequestBuilders.get("/user/findbyname/"+ testName).accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$", hasSize(1)))
.andDo(print());
}
@Test
@Order(3)
void delete() throws Exception {
// 先根据名称查出记录
String responseString = mvc.perform(MockMvcRequestBuilders.get("/user/findbyname/"+ testName).accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(jsonPath("$", hasSize(1)))
.andDo(print())
.andReturn()
.getResponse()
.getContentAsString();
// 反序列化得到数组
JsonArray jsonArray = JsonParser.parseString(responseString).getAsJsonArray();
// 反序列化得到user实例
User user = new Gson().fromJson(jsonArray.get(0), User.class);
// 执行删除
mvc.perform(MockMvcRequestBuilders.delete("/user/"+ user.getId()).accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(content().string(equalTo("1")))
.andDo(print());
}
}
- 至此编码结束，开始验证上述功能；
单元测试验证
- IDEA打开UserControllerTest.java，点击下图红框中的图标即可开始执行单元测试：
- 单元测试完成后IDEA会给出结果，如下图，红框右侧可以查看详细的测试过程数据：
- 篇幅所限，这只有少量的单元测试用例，接下来用swagger来验证每个接口；
swagger验证web接口
-
如下图，启动CurdApplication类：
-
浏览器访问：http://localhost:8080/swagger-ui.html ，即可打开swagger页面，如下图：
-
先试试新增的接口，操作如下图：
-
点击了上图红框3的Try it out!按钮后，响应信息如下图，可见操作成功：
-
限于篇幅，其他接口的测试就不逐一列出了，请您自行验证；
- 至此，MyBatis的基本增删改查和简单的联表操作的实战就完成了，接下来咱们会继续探索MyBatis的基本操作；
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