Mybatis中返回主键值方式

int insertEmployee(Employee employee);

<!-- int insertEmployee(Employee employee); -->
<!-- useGeneratedKeys属性字面意思就是“使用生成的主键” -->
<!-- keyProperty属性可以指定主键在实体类对象中对应的属性名，Mybatis会将拿到的主键值存入这个属性 -->
<insert id="insertEmployee" useGeneratedKeys="true" keyProperty="empId">
  insert into t_emp(emp_name,emp_salary)
  values(#{empName},#{empSalary})
</insert>

@Test
public void testSaveEmp() {
  EmployeeMapper employeeMapper = session.getMapper(EmployeeMapper.class);
  Employee employee = new Employee();
  employee.setEmpName("john");
  employee.setEmpSalary(666.66);
  employeeMapper.insertEmployee(employee);
  log.info("employee.getEmpId() = " + employee.getEmpId());
}

<insert id="insertUser" parameterType="User">
    <selectKey keyProperty="id" resultType="java.lang.String"
        order="BEFORE">
        SELECT UUID() as id
    </selectKey>
    INSERT INTO user (id, username, password) 
    VALUES (
        #{id},
        #{username},
        #{password}
    )
</insert>

<insert id="addUser" parameterType="blog.model.User" useGeneratedKeys="true" keyProperty="id">
......

int primary = userService.addUser(user);
int id = user.getId();

void insertBatch(List<DafSequence> list);

<insert id="insertBatch" parameterType="List" useGeneratedKeys="true" keyProperty="id">
  INSERT INTO daf_sequence
  (id,table_name, cloumn_name)
  VALUES
  <foreach collection ="list" item="sequence" index="index" separator =",">
    (#{sequence.id},#{sequence.tableName}, #{sequence.cloumnName})
  </foreach >
</insert>