pom配置

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.47</version>
        </dependency>

        <!--beetlsql-->
        <dependency>
            <groupId>com.ibeetl</groupId>
            <artifactId>beetl-framework-starter</artifactId>
            <version>1.1.35.RELEASE</version>
        </dependency>

        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>

        <!--junit测试-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version> 4.12</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.6</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

附上结构图

tb_department

CREATE TABLE `tb_department` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) DEFAULT NULL,
  `creation_time` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8mb4;

tb_employee

CREATE TABLE `tb_employee` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `hire_time` datetime DEFAULT NULL,
  `department_id` bigint(20) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8mb4;

application.properties

    server.port=80
    spring.datasource.url=jdbc:mysql://localhost:3306/demo
    spring.datasource.username=root
    spring.datasource.password=admin
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    
    #beetlsql
    //DAO包路径，否则无法注入
    beetlsql.basePackage=com.terry
    beetlsql.daoSuffix=DAO
    //(源码的注释)下划线命名转换,数据库 Sys_User,对应类SysUser,列user_Id,对应属性userId
    beetlsql.nameConversion=org.beetl.sql.core.UnderlinedNameConversion
    beetlsql.sqlPath=/sql

先从department开始把,毕竟没有部门，哪里来的员工

BaseModel

@Getter@Setter
public class BaseModel implements Serializable {

    //如果是自增主键，并且也叫id，则AutoID可以省略，更多请参考beetl官网
    @AutoID
    private Long id;
}

Department

@Getter
@Setter
@Table(name="tb_department")
public class Department extends BaseModel {

    private String title;

    private Date creationTime;

}

DepartmentDAO，这里直接继承BaseMapper就可以了

public interface DepartmentDAO extends BaseMapper<Department> {
}

DepartmentService

@Service
public class DepartmentService {

    @Autowired
    private DepartmentDAO departmentDAO;

    public Department add(Department department){
        departmentDAO.insertTemplate(department,true);
        return departmentDAO.unique(department.getId());
    }

    public List<Department> listAll(){
        return departmentDAO.all();
    }

    public Department selectById(Long id){
        return departmentDAO.unique(id);
    }

}

DepartmentController

@RestController
@RequestMapping("/dep")
public class DepartmentController {

    @Autowired
    private DepartmentService departmentService;

    @PostMapping("/add")
    @ResponseBody
    public String add(Department department){
        department.setCreationTime(new Date());
        Department de = departmentService.add(department);
        return JSON.toJSONString(de);
    }

    @GetMapping("list")
    public String listAll(){
        List<Department> departments = departmentService.listAll();
        return JSON.toJSONString(departments);
    }

}

接下来是Employee部分

@Getter@Setter
@Table(name="tb_employee")
public class Employee extends BaseModel{

    private String name;

    private Date hireTime;

    private Long departmentId;

    private Department department;
}

EmployeeDAO

public interface EmployeeDAO extends BaseMapper<Employee> {

    //这里自定义了一个方法
    @SqlStatement(params = "departmentId",returnType = Employee.class)
    List<Employee> selectByDepartmentId(Long departmentId);
}

EmployeeService

@Service
public class EmployeeService {

    @Autowired
    private EmployeeDAO employeeDAO;

    @Autowired
    private DepartmentDAO departmentDAO;

    public Employee add(Employee employee){
        employeeDAO.insertTemplate(employee,true);
        return employeeDAO.unique(employee.getId());
    }

    public List<Employee> listAll(){
        List<Employee> list = employeeDAO.all();
        list.forEach(m->m.setDepartment(departmentDAO.unique(m.getDepartmentId())));
        return list;
    }

    public List<Employee> selectByDepartmentId(Long departmentId) {
        List<Employee> list = employeeDAO.selectByDepartmentId(departmentId);
        list.forEach(m->m.setDepartment(departmentDAO.unique(m.getDepartmentId())));
        return list;
    }

    public int update(Employee employee) {
        return employeeDAO.updateTemplateById(employee);
    }
}

EmployeeController

@RestController
@RequestMapping("/emp")
public class EmployeeController {

    @Autowired
    private EmployeeService employeeService;


    @PostMapping("/add")
    public String add(Employee employee){
        employee.setHireTime(new Date());
        Employee emp = employeeService.add(employee);
        return JSON.toJSONString(emp);
    }

    @GetMapping("/all")
    public String all(){
        return JSON.toJSONString(employeeService.listAll());
    }

    @GetMapping("/getByDepId")
    public String get(Long departmentId){
        return JSON.toJSONString(employeeService.selectByDepartmentId(departmentId));
    }

    @PostMapping("/update")
    public String update(Employee employee){
        int i = employeeService.update(employee);
        if (i==0){
            return "更新失败";
        }else return "更新成功";
    }

}

employee.md

selectByDepartmentId
===
select * from tb_employee where 1=1
@if(isNotEmpty(departmentId)){
 and department_id = #departmentId#
@}

启动类

@SpringBootApplication
public class ApiApplication {
    public static void main(String[] args) {
        SpringApplication.run(ApiApplication.class,args);
    }
}

大功告成啦~