Mybatis注解增删改查的实例代码

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

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原文链接：https://juejin.cn/post/6933495094414835726

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