Mybatis注解实现增删改查，如何编写实例代码？

本文共计582个文字，预计阅读时间需要3分钟。

要完成语句映射，可以使用以下方法：

+ 使用Java注释配置语句映射。+ 映射语句无需XML配置，直接通过Java注释实现。+ 使用Java注释简化语句映射，使代码更简洁。+ 对于复杂或微妙的语句，注释映射可能不如XML配置灵活。

要点

有另一种方法来完成语句映射。 它们映射的语句可以不用 XML 来配置，而可以使用 Java 注解来配置。

使用注解来映射简单语句会使代码显得更加简洁，但对于稍微复杂一点的语句，Java 注解不仅力不从心，还会让你本就复杂的 SQL 语句更加混乱不堪。

如果你需要做一些很复杂的操作，最好用 XML 来映射语句。

需要在config.xml中注册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
可以先开启事务自动提交

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(); } }

因为已经自动提交了，所以不需要sqlSession.commit();

删

注解@Param

只能用于基本数据类型

传入的参数只能和sql语句中参数一样

多个参数

样例

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(); } }

总结

到此这篇关于Mybatis注解增删改查的文章就介绍到这了,更多相关Mybatis注解增删改查内容请搜索易盾网络以前的文章或继续浏览下面的相关文章希望大家以后多多支持易盾网络！