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

野性酷女 2024-02-29 06:40 77阅读 0赞

**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">
    
        <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>
    
      <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>