mybatis的sql转化为sql语句

MyBatis的SQL语句是通过XML文件来描述的，需要通过解析XML文件来生成SQL语句。以下是一个示例：

XML文件：

<?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.example.mapper.UserMapper">
  <select id="getUserById" parameterType="int" resultType="com.example.entity.User">
    SELECT * FROM user WHERE id = #{id}
  </select>
</mapper>

Java代码：

SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession session = sqlSessionFactory.openSession();
UserMapper userMapper = session.getMapper(UserMapper.class);
User user = userMapper.getUserById(1);
session.close();

MyBatis会解析XML文件，将`getUserById`标识的SQL语句转化为如下的SQL语句：

SELECT * FROM user WHERE id = ?

其中`#{id}`会被转化为`?`，MyBatis会将传入的参数绑定到`?`上。