11.2 基于注解的动态SQL3 update

生成动态SQL的方法

/MyADynamicSQLTest/src/mapper/EmployeeDynamicSQLProvider.java

public String updateEmployeeByPO(Employee employee)
{
    return new SQL(){
        {
            // 在这里写上动态SQL的生成逻辑...
            UPDATE("tb_employee");
            if(employee.getLoginname() != null)
            {
                SET("loginname=#{loginname}");
            }
            if(employee.getPassword() != null)
            {
                SET("password=#{password}");
            }
            if(employee.getName() != null)
            {
                SET("name=#{name}");
            }
            if(employee.getSex() != null)
            {
                SET("sex=#{sex}");
            }
            if(employee.getAge() != null)
            {
                SET("age=#{age}");
            }
            if(employee.getPhone() != null)
            {
                SET("phone=#{phone}");
            }
            if(employee.getSal() != null)
            {
                SET("sal=#{sal}");
            }
            if(employee.getState() != null)
            {
                SET("state=#{state}");
            }
            WHERE("id=#{id}");
        }
    }.toString();
}

mapper接口方法

/MyADynamicSQLTest/src/mapper/EmployeeMapper.java

@UpdateProvider(
    type = EmployeeDynamicSQLProvider.class,
    method = "updateEmployeeByPO"
)
void updateEmployeeByPO(Employee employee);

测试类

/MyADynamicSQLTest/src/test/UpdateTest.java

package test;

import org.apache.ibatis.session.SqlSession;
import domain.Employee;
import fractory.SqlSessionFactoryTools;
import mapper.EmployeeMapper;

public class UpdateTest {
    public static void main(String[] args) {
        SqlSession sqlSession = null;
        try {
            // 加载mybatis-config.xml,获取SqlSession实例
            sqlSession = SqlSessionFactoryTools.getSqlSession();
            EmployeeMapper employeeMapper = sqlSession.getMapper(EmployeeMapper.class);
            // 查找要修改的行
            Employee employee = employeeMapper.selectEmployeeById(3);
            System.out.println("-------------------------------------------------");
            // 如果找到
            if (employee != null) {
                System.out.println("修改之前的员工信息");
                System.out.println(employee);
                System.out.println("-------------------------------------------------");
                // 创建一个新对项，保存更新后的信息
                Employee employeeUpdate = new Employee();
                // 主键id不更新
                employeeUpdate.setId(employee.getId());
                // 更新其他信息
                // employeeUpdate.setLoginname();
                // employeeUpdate.setPassword();
                employeeUpdate.setName("修改之后的姓名");
                employeeUpdate.setSex("男");
                // employeeUpdate.setAge(15);
                // employeeUpdate.setPhone();
                // employeeUpdate.setSal(123.1);
                // employeeUpdate.setState("员工");
                // 执行更新语句
                employeeMapper.updateEmployeeByPO(employeeUpdate);
                System.out.println("-------------------------------------------------");
                // 再吃查询
                employee = employeeMapper.selectEmployeeById(3);
                System.out.println("-------------------------------------------------");
                // 查看是否更新成功
                System.out.println(employee);
            }
            sqlSession.commit();
        } catch (Exception e) {
            // 出错回滚事务
            sqlSession.rollback();
            e.printStackTrace();
        } finally {
            // 关闭会话
            if (sqlSession != null)
                sqlSession.close();
        }
    }
}

运行效果

DEBUG [main] ==>  Preparing: select * from tb_employee where id=? 
DEBUG [main] ==> Parameters: 3(Integer)
DEBUG [main] <==      Total: 1
-------------------------------------------------
修改之前的员工信息
Employee [id=3, loginname=xiaoli, password=xiaoli, name=小丽, sex=女, age=23, phone=123456789123, sal=7800.0, state=active]
-------------------------------------------------
DEBUG [main] ==>  Preparing: UPDATE tb_employee SET name=?, sex=? WHERE (id=?) 
DEBUG [main] ==> Parameters: 修改之后的姓名(String), 男(String), 3(Integer)
DEBUG [main] <==    Updates: 1
-------------------------------------------------
DEBUG [main] ==>  Preparing: select * from tb_employee where id=? 
DEBUG [main] ==> Parameters: 3(Integer)
DEBUG [main] <==      Total: 1
-------------------------------------------------
Employee [id=3, loginname=xiaoli, password=xiaoli, name=修改之后的姓名, sex=男, age=23, phone=123456789123, sal=7800.0, state=active]