Django CharField vs TextField [英] Django CharField vs TextField

问题描述

Django中的 CharField（）和 TextField（）有什么区别？ 文档表示 CharField（）应用于较小的字符串，而 TextField（）应用于较大的字符串。好的，但是在小和大之间画线呢？

解决方案

这是RDBMS的 varchar之间的区别（或类似） - 通常以最大长度指定，并且在性能或存储方面可能更有效 - 而 text （或类似的）类型 - 通常仅受硬编码实现限制（而不是DB模式）的限制。

PostgreSQL 9具体说，这三种类型之间没有性能差异，但是AFAIK在例如MySQL，所以这是要记住的一点。

一个很好的经验法则是你使用 CharField 您需要限制最大长度 TextField 否则。

这不是Django特有的，也是。 / p>

What is the difference between CharField() and TextField() in Django? The documentation says that CharField() should be used for smaller strings and TextField() should be used for larger strings. Okay, but where is the line drawn between "small" and "large"? What's going on under the hood here that makes this the case?

解决方案

It's a difference between RDBMS's varchar (or similar) — those are usually specified with a maximum length, and might be more efficient in terms of performance or storage — and text (or similar) types — those are usually limited only by hardcoded implementation limits (not a DB schema).

PostgreSQL 9, specifically, states that "There is no performance difference among these three types", but AFAIK there are some differences in e.g. MySQL, so this is something to keep in mind.

A good rule of thumb is that you use CharField when you need to limit the maximum length, TextField otherwise.

This is not really Django-specific, also.

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