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?
解决方案
String, in general, should be used for short text. For example, it is a VARCHAR(255) under MySQL.
Text uses the larger text from the database, like, in MySQL, the type TEXT.
For information on how this works and the internals in MySQL and limits and such, see the other answer by Pekka.
If you are requesting, say, a paragraph, I would use text. If you are requesting a username or email, use string.
