笔记要点-----内置参数_parameter&_databaseId      用处: 迅速切换数据库,执行一条多分支的sql语句即可;

1.定义接口

public interface EmployeeMapper_DynamicSQL {    public List
     
       getEmpsTestInnerParameter(Employee employee);//测试内部参数}
     

2.定义XML映射文件

         
                             select * from tbl_employee                            where last_name = #{_parameter.lastName}                                        select * from tbl_employee        

3.编写测试代码

public class test_tp48 {    public SqlSessionFactory getSqlSessionFactory() throws IOException {        String resource = "mybatis-config.xml";        InputStream inputStream = Resources.getResourceAsStream(resource);        return new SqlSessionFactoryBuilder().build(inputStream);    }    @Test    public void test11() throws Exception {        SqlSession openSession = getSqlSessionFactory().openSession();        try {            System.out.println("++++++++++---- tp48.测试动态sql_内置参数_parameter&_databaseId");            EmployeeMapper_DynamicSQL mapper = openSession.getMapper(EmployeeMapper_DynamicSQL.class);            List
      
        list = mapper.getEmpsTestInnerParameter(null);            for(Employee e:list)                System.out.println(e);            openSession.commit();        } finally {            openSession.close();        }    }}
      

测试结果

++++++++++---- tp48.测试动态sql_内置参数_parameter&_databaseIdDEBUG 12-05 17:45:17,805 ==>  Preparing: select * from tbl_employee   (BaseJdbcLogger.java:145) DEBUG 12-05 17:45:17,828 ==> Parameters:   (BaseJdbcLogger.java:145) DEBUG 12-05 17:45:17,845 <==      Total: 8  (BaseJdbcLogger.java:145) Employee{id=1, lastName='Jerry2333', email='233@...', gender='1', dept=null}Employee{id=4, lastName='葫芦娃', email='葫芦娃@163.com', gender='0', dept=null}Employee{id=5, lastName='葫芦娃e', email='qwq@qq.com', gender='1', dept=null}Employee{id=6, lastName='null', email='xxx@qq.com', gender='1', dept=null}Employee{id=7, lastName='tom', email='tom@163.com', gender='0', dept=null}Employee{id=8, lastName='frak', email='frak@163.com', gender='1', dept=null}Employee{id=9, lastName='smith', email='smith@qq.com', gender='1', dept=null}Employee{id=10, lastName='aliex', email='aliex@qq.com', gender='0', dept=null}