1. Mybatis简单操作

0. pom.jar

<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.3</version>
        </dependency>

 

1. mapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xing.mapper.AccountMapper">
    <delete id="deleteAll">
        delete from `account`;
    </delete>
</mapper>

2. SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql:///student" />
                <property name="username" value="root" />
                <property name="password" value="123" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <!-- 加载sql语句的配置文件 -->
        <mapper resource="mapper.xml"/>
    </mappers>
</configuration>

 

3. Interface AccountMapper　

package com.xing.mapper;
import com.xing.beans.Account;
import java.util.List;
public interface AccountMapper {
    void deleteAll();
    List<Account> findAll();
    void deleteById( Integer id);
    Account findById(Integer id);
    double findMoneyById(Integer id);
}

4. Class Test

package com.xing.test2;

import com.xing.beans.Account;
import com.xing.mapper.AccountMapper;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.util.List;

public class Test1 {
    @Test
    public void te1() throws IOException {
        SqlSession sqlSession = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("SqlMapConfig.xml")).openSession();
        AccountMapper mapper = sqlSession.getMapper(AccountMapper.class);
        mapper.deleteById(2);
        sqlSession.commit();
    }

    @Test
    public void test2() throws IOException {
        SqlSession sqlSession = new SqlSessionFactoryBuilder().build(Resources.getResourceAsStream("SqlMapConfig.xml")).openSession();
        AccountMapper mapper = sqlSession.getMapper(AccountMapper.class);
        List<Account> all = mapper.findAll();
29 }

注意： 

　　1. 在做查询操作时，配置 mapper.xml 里 返回值类型 写为 对象不用写集合，当查询返回是对象集合时，会自动的转换的