Mybatis配置文件(mybatis-config.xml)和Mapper映射文件(XXXMapper.xml)模板

配置文件

${dirver} ---> com.mysql.jdbc.Driver

${url} ---> jdbc:mysql://localhost:3306/数据库名

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
  <environments default="development">
<!--配置数据源，即数据库信息-->
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
<!--引入映射文件,路径：src/main/resources/mapper/BlogMapper.xml-->
  <mappers>
    <mapper resource="mapper/BlogMapper.xml"/>
  </mappers>
</configuration>

Mapper映射文件

mybatis面向接口编程，需要保持两个一致性：

(1)映射文件中的namespace(命名空间)和Mapper接口的全类名保持一致；

(2)映射文件中sql语句中的id需要和Mapper接口的方法名保持一致；

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.mybatis.example.BlogMapper">
  <select id="selectBlog" resultType="Blog">
    select * from Blog where id = #{id}
  </select>
</mapper>