会员版20就业课20mybatis笔记第二天讲义

mybatis第四步：编写SqlMapConfig.xml 3、SQL语句的配置 ID在持久层接口中添加findById根据id@paramUserfindById(Integer<selectid="findById"resultType="com.itheima.select*fromuserwhereid=#{uid}.User"*<p>Title:*:/publicclassMybastisCRUDTestprivateInputStreaminprivateSqlSessionFactoryprivateSqlSessionprivateIUserDaopublicvoidtestFindOne()Useruser=}publicvoidinit()throwsException in=SqlSessionFactoryBuilderbuilder=newfactory=session= userDao=}publicvoiddestroy() }}@param@returnintsaveUser(User<insertid="saveUser"insertintouser(username,birthday, User对象，此处要写User对象中的属性名称。它用的是ognl表达式。ObjectGraphicNavigationLanguage对象图导航语言语法格式就是使用#{对象.对象}publictestSave(){Userusernewuser.setUsername("modifyUserproperty"); user.setBirthday(newDate());} publicvoiddestroy()throws当于我们要在新增后将自动增长auto_increment的值返回。<insertid="saveUser"<selectKeykeyColumn="id"keyProperty="id"resultType="int">selectlast_insert_id();insertintouser(username,birthday, @paramintupdateUser(Userupdateusersetusername=#{username},birthday=#{birthday},address=#{address}whereid=#{id}publicvoidtestUpdateUser()throwsUseruser= intres=userDao.updateUser(user);}@paramintintdeleteUser(Integer<deleteid="deleteUser"parameterType="java.lang.Integer">deletefromuserwhereid=#{uid}publicvoidtestDeleteUser()throwsExceptionintres=userDao.deleteUser(52);}@param<selectid="findByName".User"select*fromuserwhereusernamelikepublicvoidfor(Useruserusers){}}识%。配置文件中的#{username}SQL语句显示为“？”。<selectid="findByName"parameterType="string"resultType="com.itheima.select*fromuserwhereusernamelike'%${value}%'publicvoidfor(Useruser}}型值，#{}括号中可以是value或其它名称。 int 录条数--<selectid="findTotal"selectcount(*)frompublicvoidtestFindTotal()throwsExceptionintres=userDao.findTotal();}MybatisJDBC parameterType我们在上一章节中已经介绍了我们在上一章节中已经介绍了SQL语句传参，使用 的parameterType属性来设定。该属性的取值可以 基本类型和String我们可以直接写类型名称，也可以使用包名类名的方式，例如：可以参考TypeAliasRegistery.class的源码。pojo 编写*<p>Title::*:/publicclassQueryVoimplementsSerializableprivateUserpublicUsergetUser()return}publicvoidsetUser(Useruser)this.user=}}*<p>Title:*:/publicinterfaceIUserDao@param}<selectid="findByVo" select*fromuserwhereusernamelike#{user.username};publicvoidQueryVovonewQueryVo();Useruser=newUser();List<User>users=for(Useru:{}}resultType 面的CRUD案例中已经对此属性进行过应用了。需要注意的是，它和parameterType一样，如果 Dao int 录条数--<selectid="findTotal"resultType="int">selectcount(*)fromuser;DaoList<User><selectid="findAll"resultType="com.itheima.select*fromuser*<p>Title::*:/publicclassUserimplementsSerializableprivateIntegeruserId;privateStringuserName;privateDateuserBirthday;privateStringuser privateStringpublicIntegergetUserId()return}publicvoidsetUserId(IntegeruserId)this.userId=}publicStringgetUserName()return}publicvoidsetUserName(StringuserName)this.userName=}publicDategetUserBirthday()return}publicvoidsetUserBirthday(DateuserBirthday)thisthis.userBirthday=}publicString ()return }publicvoid (String ) = }publicStringgetUserAddress()return}publicvoidsetUserAddress(StringuserAddress)this.userAddress=}publicStringtoString()+userBirthday+", + +",userAddress="+userAddress+}}DaoList<User><selectid="findAll"resultType="com.itheima.select*fromuserpublicvoidtestFindAll()List<User>users=for(Useruser:{}}<selectid="findAll"selectidasuserId,usernameasuserName,birthdayasuserBirthday,asuser ,addressasuserAddressfromuserresultMap定义<resultMap .User"<idcolumn="id"<result " <selectid="findAll"resultMap="userMap">select*fromuserpublicvoid{List<User>users=for(Useruser:{}} MybatisDAO*<p>Title:*:/publicinterfaceIUserDaoList<User>@paramUserfindById(Integer@param@returnintsaveUser(User@paramintupdateUser(User@paramintdeleteUser(Integer int}*<p>Title:*:/publicclassUserDaoImplimplementsIUserDaothis.factory=}publicList<User>findAll()SqlSessionsession=List<User>users=session.selectList("com.itheima.dao.IUserDao.findAll");return}publicUserfindById(Integer{SqlSessionsession=Useruser=session.selectOne("com.itheima.dao.IUserDao.findById",userId);return}publicintsaveUser(Useruser)SqlSessionsession=intres=session.insert("com.itheima.dao.IUserDao.saveUser",user);return}publicintupdateUser(Useruser)SqlSessionsession=intres=session.update("com.itheima.dao.IUserDao.updateUser",user);return}publicintdeleteUser(Integer{SqlSessionsession=intres=session.delete("com.itheima.dao.IUserDao.deleteUser",userId);return}publicintfindTotal()SqlSessionsession=intres=session.selectOne("com.itheima.dao.IUserDao.findTotal");return}}<!DOCTYPEPUBLIC"-////DTDMapper <mapper<selectid="findAll"resultType="com.itheima. select*fromuser select*fromuserwhereid=ObjectGraphicNavigationLanguage对象图导航语言语法格式就是使用#{对象.对象}<insertid="saveUser" <selectKeykeyColumn="id"keyProperty="id"resultType="int">selectlast_insert_id(); <updateid="updateUser"parameterType="com.itheima. username=#{username},birthday=#{birthday},=#{},address=#{address}where<<deleteid="deleteUser"parameterType="java.lang.Integer">deletefromuserwhereid=#{uid} <selectid="findTotal"resultType="int">selectcount(*)fromuser;*<p>Title:*:/publicclassMybastisCRUDTestprivateInputStreaminprivateIUserDaopublicvoidtestFindAll()List<User>users=for(Useruser:{}}publicvoidtestFindOne()Useruser=}publicvoidtestSaveUser()throws{Useruser=newUser();user.setUsername("mybatisdaouser");intres=userDao.saveUser(user);}publicvoidtestUpdateUser()throwsUseruser= intres=userDao.updateUser(user);}publicvoidtestDeleteUser()throwsExceptionintres=userDao.deleteUser(56);}publicvoidtestFindTotal()throwsExceptionintres=userDao.findTotal();}p