原始mybatis

创建一个maven模块不要有父级
依赖
org.mybatis
mybatis
3.5.1

mysql
mysql-connector-java
5.1.47

日志依赖
org.slf4j
slf4j-log4j12
1.7.25
要加一个配置模板log4j.properties不用怎么改考一个
log4j.rootLogger=ERROR日志级别,CONSOLE记录的存放地址

LIMIT CATEGORIES具体的显示日志
log4j.logger.路径=ALL

主类写
String resource = "org/mybatis/example/Configuration.xml";
Reader reader = Resources.getResourceAsReader(resource);
sqlMapper = new SqlSessionFactoryBuilder().build(reader);

Sqlsession session = sessionFactory.openSession();

try{
UserMapper userMappser = session.getMappser(UserMappser.class);
System.out.println(userMapper.select());
}finally{
session.close();
}

模型类
mapper类
@Select("select id,account.password from user")
List<User> select();
配置文件中写
<?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>
<typeAliases>类型别名
1.<typeAlias......一个类型给一个名字
2.<package name="类的包路径”/>Mapper.xml中resultType可以只写类名，用处不大
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/> 驱动在mysql-connector-java中
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="org/mybatis/example/BlogMapper.xml"/>选择有class等
1.<mapper class="mapper类的路径"/>
2.<package name="mapper的包路径"/>
</mappers>
</configuration>