第四天

数据层--通过Java代码来实现对数据库中数据的操作（增删改查）

JDBC

mybatis--mapper包名

接口：

　　静态常量 public static final

　　抽象方法 void f1();

Mybatis 的Mapper层（dao层）创建

 @Mapper
 public interface DepartmentMapper {
     //增
     @Insert("insert into department(code,name,tel)valus(#{code},#{name},#{tel})")
     int insert(DepartmentModel model);
     //删
     @Delete("delete from department where code=#{code}")
     int delete(DepartmentModel model);
     //改
     @Update("update department set name=#{name},tel=#{tel} where code=#{code}")
     int update(DepartmentModel model);
     //查询所有
     @Select("select name,code,tel from department")
     DepartmentModel selectModel(DepartmentModel model);
     //模糊查询
     @Select("select name,code,tel from department where name like #{name}")
     List<DepartmentModel> selectList(DepartmentModel model);
 }
 ?