mybaites连接数据库

mybatis入门实例连接数据库进行查询

1.新建项目，添加mybatis和mysql的jar包

2.在mysql中新建表user[id,name,age]

CREATE TABLE users (
id int(11) NOT NULL auto_increment,
NAME varchar(50) default NULL,
age int(11) default NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

3.新建User类，与db的表对应
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按 Ctrl+C 复制代码

4.在src目录下面新建mybatis的配置文件conf.xml
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按 Ctrl+C 复制代码

5.新建userMapper.xml，添加数据库操作语句
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按 Ctrl+C 复制代码

将mapper配置文件添加到mybatis的配置文件conf.xml的mappers标签中：

<mappers>
    <mapper resource="com/mlxs/mybatis/test1/userMapper.xml" />
    
</mappers>

6.添加测试类，获取一个user的信息
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按 Ctrl+C 复制代码

7.结果

User [id=1, name=Tom, age=12]

8.测试增删改查，导入junit包，添加测试类
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import java.util.List;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.junit.Test;

import com.mlxs.mybatis.util.MyBatisUtil;

public class _Test2UserCrud {

@Test
public void addUser(){
    SqlSessionFactory sessionFactory = MyBatisUtil.getSessionFactory();
    SqlSession sqlSession = sessionFactory.openSession();
    String statement = "com.mlxs.mybatis.test.userMapper.addUser";
    int count = sqlSession.insert(statement, new User(0, "add1", 10));
    sqlSession.commit();
    sqlSession.close();
    System.out.println("add count:"+count);
}
@Test
public void updateUser(){
    SqlSessionFactory sessionFactory = MyBatisUtil.getSessionFactory();
    SqlSession sqlSession = sessionFactory.openSession();
    String statement = "com.mlxs.mybatis.test.userMapper.updateUser";
    int count = sqlSession.update(statement, new User(3, "update2", 100));
    sqlSession.commit();
    sqlSession.close();
    System.out.println("update count:"+count);
}
@Test
public void delUser(){
    SqlSessionFactory sessionFactory = MyBatisUtil.getSessionFactory();
    boolean autoCommit = true;//自动提交，不需手动commit
    SqlSession sqlSession = sessionFactory.openSession(autoCommit);
    String statement = "com.mlxs.mybatis.test.userMapper.deleteUser";
    int count = sqlSession.delete(statement, 4);
    sqlSession.close();
    System.out.println("del count:"+count);
}
@Test
public void selectAll(){
    SqlSessionFactory sessionFactory = MyBatisUtil.getSessionFactory();
    boolean autoCommit = true;//自动提交，不需手动commit
    SqlSession sqlSession = sessionFactory.openSession(autoCommit);
    String statement = "com.mlxs.mybatis.test.userMapper.selectAllUsers";
    List<User> userList = sqlSession.selectList(statement);
    sqlSession.close();
    System.out.println(userList);
}

}

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mybaites连接数据库

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