<?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.itsoku.lesson004.mapper.ConcurrencySafeMapper">

    <!-- 使用乐观锁更新数据 -->
    <update id="optimisticUpdate">
        update t_concurrency_safe set version = version + 1 where safe_key = #{safeKey} and version = #{version}
    </update>

</mapper>