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Mybatis注解增刪改查的實(shí)例代碼

更新時(shí)間：2021年03月04日 11:14:46 作者：KittyGuy

這篇文章主要給大家介紹了關(guān)于Mybatis注解增刪改查的相關(guān)資料，文中通過(guò)示例代碼介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來(lái)一起學(xué)習(xí)學(xué)習(xí)吧

要點(diǎn)

有另一種方法來(lái)完成語(yǔ)句映射。它們映射的語(yǔ)句可以不用 XML 來(lái)配置，而可以使用 Java 注解來(lái)配置。

使用注解來(lái)映射簡(jiǎn)單語(yǔ)句會(huì)使代碼顯得更加簡(jiǎn)潔，但對(duì)于稍微復(fù)雜一點(diǎn)的語(yǔ)句，Java 注解不僅力不從心，還會(huì)讓你本就復(fù)雜的 SQL 語(yǔ)句更加混亂不堪。

如果你需要做一些很復(fù)雜的操作，最好用 XML 來(lái)映射語(yǔ)句。

需要在config.xml中注冊(cè)Java接口

<mappers>
 <mapper class="com.mybatis.DAO.PeopleMapper"/>
</mappers>

要用class=

查

public interface PeopleMapper {
 @Select("select * from people")
 List<People> getPeopleList();
}

增
可以先開(kāi)啟事務(wù)自動(dòng)提交

public static SqlSession getSqlSession(){
  return sqlSessionFactory.openSession(true);
 }
}

Mapper.java

public interface PeopleMapper {
 @Select("select * from people")
 List<People> getPeopleList();
 @Insert("insert into people(id, name, age, address) VALUES (#{id},#{name},#{age},#{address})")
 int addPeople(People people);
}

test

public class PeopleDAOtest {
 @Test
 public void print() {
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  PeopleMapper peopleMapper = sqlSession.getMapper(PeopleMapper.class);
  List<People> people = peopleMapper.getPeopleList();
  for (People p :people){
   System.out.println(p);
  }
  sqlSession.close();
 }
 @Test
 public void add(){
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  PeopleMapper peopleMapper = sqlSession.getMapper(PeopleMapper.class);
  peopleMapper.addPeople(new People(6,"圣迭戈",456,"啥地方"));
  print();
 }
}

因?yàn)橐呀?jīng)自動(dòng)提交了，所以不需要sqlSession.commit();

刪

注解@Param

只能用于基本數(shù)據(jù)類(lèi)型

傳入的參數(shù)只能和sql語(yǔ)句中參數(shù)一樣

多個(gè)參數(shù)

樣例

public interface PeopleMapper {
 @Delete("delete people from people where id=#{uid}")
 int delPeople(@Param("uid") int i);
}

test

public class PeopleDAOtest {
 @Test
 public void del(){
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  PeopleMapper peopleMapper = sqlSession.getMapper(PeopleMapper.class);
  peopleMapper.delPeople(6);
  print();
 }
}

改

Mapper.java

public interface PeopleMapper {
 @Update("update mybatis.people set name=#{name} ,age=#{age} ,address=#{address} where id=#{id}")
 int updateP(People people);
}

test

public class PeopleDAOtest {
 @Test
 public void update(){
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  PeopleMapper peopleMapper = sqlSession.getMapper(PeopleMapper.class);
  peopleMapper.updateP(new People(5,"圣迭戈",456,"啥地方"));
  print();
 }
}