Alter 和 Update SQL 的区别 [英] Difference between Alter and Update SQL

问题描述

我正在忙于研究 MySQL，我了解 update 用于更新表中的记录或行.那么 alter do 有什么不同呢?好像是一样的.

I am busy studying MySQL and I understand that update is used to update a record or row in a table. So what does alter do that is so different? Seems like they are the same.

谢谢，我们将不胜感激.

Thanks, any help will be appreciated.

推荐答案

ALTER 是一个 DDL(数据定义语言)语句.而 UPDATE 是 DML(数据操作语言)语句.ALTER 用于更新表的结构(添加/删除字段/索引等).而 UPDATE 用于更新数据.

ALTER is a DDL (Data Definition Language) statement. Whereas UPDATE is a DML (Data Manipulation Language) statement. ALTER is used to update the structure of the table (add/remove field/index etc). Whereas UPDATE is used to update data.

这篇关于Alter 和 Update SQL 的区别的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！