關於mybatis的 中的keyColumn

<mapper namespace="com.dao.EmployeeDao">

    <insert id="insert">
        <selectKey order="BEFORE" keyColumn="employeeId,employeeGender" keyProperty="employeeId,employeeGender" resultType="com.entity.Employee">
            select employee_id employeeId,employee_gender employeeGender from employee where employee_id=13
        </selectKey>
        insert into subtable(employee_id,employee_name,employee_gender) values (#{employeeId},"mdzz",#{employeeGender})
    </insert>
</mapper>

　　keyColumn是要和select語句中的表名相對應的實體類的字段對應的，但同時他也要和select語句中的列名對應，因此要取別名一致。

keyProperty是和insert語句中的values內的參數一致，也就是和insert語句中的表的對應實體類的字段一致，才可以通過反射完成

java代碼

public interface EmployeeDao {
    int insert(Employee employee);
}

　　測試代碼

@Test
    public void testInsert() {
        Employee employee = new Employee();
        EmployeeDao employeeDao = MapperFactory.generateMapper(EmployeeDao.class);
        employeeDao.insert(employee);
        System.out.println(employee);
    }

　　表說明：創建了一個employee表，和一個副標subtable，列和employee完全一樣，列名都是通過“_”連接的

employee | CREATE TABLE `employee` (
  `employee_id` int(11) NOT NULL AUTO_INCREMENT,
  `employee_name` char(30) DEFAULT NULL,
  `employee_gender` binary(1) DEFAULT NULL,
  `employee_salary` decimal(10,2) DEFAULT NULL,
  `dept_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`employee_id`)
) ENGINE=InnoDB AUTO_INCREMENT=24 DEFAULT CHARSET=utf8mb4 |