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?
In some cases it is tied to how the field is used. In some DB engines the field differences determine how (and if) you search for text in the field. CharFields are typically used for things that are searchable, like if you want to search for "one" in the string "one plus two". Since the strings are shorter they are less time consuming for the engine to search through. TextFields are typically not meant to be searched through (like maybe the body of a blog) but are meant to hold large chunks of text. Now most of this depends on the DB Engine and like in Postgres it does not matter.
Even if it does not matter, if you use ModelForms you get a different type of editing field in the form. The ModelForm will generate an HTML form the size of one line of text for a CharField and multiline for a TextField.
I had an strange problem and understood an unpleasant strange difference:
when I get an URL from user as an CharField and then and use it in html a tag by href, it adds that url to my url and that's not what I want. But when I do it by Textfield it passes just the URL that user entered.
look at these:
my website address: http://myweb.com
CharField entery: http://some-address.com
when clicking on it: http://myweb.comhttp://some-address.com
TextField entery: http://some-address.com
when clicking on it: http://some-address.com
I must mention that the URL is saved exactly the same in DB by two ways but I don't know why result is different when clicking on them
CharField
has max_length of 255
characters while TextField
can hold more than 255
characters. Use TextField
when you have a large string as input. It is good to know that when the max_length
parameter is passed into a TextField
it passes the length validation to the TextArea
widget.
For eg.,. 2 fields are added in a model like below..
description = models.TextField(blank=True, null=True)
title = models.CharField(max_length=64, blank=True, null=True)
Below are the mysql queries executed when migrations are applied.
for TextField
(description) the field is defined as a longtext
ALTER TABLE `sometable_sometable` ADD COLUMN `description` longtext NULL;
The maximum length of TextField
of MySQL is 4GB according to string-type-overview.
for CharField
(title) the max_length(required) is defined as varchar(64)
ALTER TABLE `sometable_sometable` ADD COLUMN `title` varchar(64) NULL;
ALTER TABLE `sometable_sometable` ALTER COLUMN `title` DROP DEFAULT;
Source: Stackoverflow.com