mysql中的字符串长度是否有限制? [英] Are there any limits on length of string in mysql?
问题描述
我在Rails中使用MySQL数据库.我创建了一个string
类型的字段.它的长度有限制吗? text
类型如何?
同样,由于text
是可变大小的,我相信使用文本对象会带来额外的成本.如果有的话,他们能变得有多重要?
I am using MySQL data base with Rails. I have created a field of type string
. Are there any limits to its length? What about type text
?
Also as text
is variable sized, I believe there would be extra costs associated with using text objects. How important can they get, if at all?
推荐答案
通常,字符串应用于短文本.例如,它是MySQL下的VARCHAR(255)
.
String, in general, should be used for short text. For example, it is a VARCHAR(255)
under MySQL.
文本使用数据库中较大的文本,例如在MySQL中,类型为TEXT
.
Text uses the larger text from the database, like, in MySQL, the type TEXT
.
有关此工作方式以及MySQL内部和限制等信息,请参阅Pekka的其他答案.
For information on how this works and the internals in MySQL and limits and such, see the other answer by Pekka.
例如,如果您要一段,我将使用文本.如果您要输入用户名或电子邮件,请使用字符串.
If you are requesting, say, a paragraph, I would use text. If you are requesting a username or email, use string.
这篇关于mysql中的字符串长度是否有限制?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!