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sqldjangodatabasestoragedjango-model-field
Jonathan Gleason
Jonathan Gleason

Reputation: 4727

What's 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?

Upvotes: 422

Views: 212321

Answers (5)

Murad
Murad

Reputation: 1162

When you want to store long text, use TextField, or when you want shorter strings then CharField is useful.

article_title = models.CharField(max_length=150)
article_body = models.TextField()

Upvotes: 4

Njeru Cyrus
Njeru Cyrus

Reputation: 1789

Use TextField when you have a large string as input. When the max_length parameter is passed into a TextField it passes the length validation to the TextArea widget.

Upvotes: 15

SuperNova
SuperNova

Reputation: 27486

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;

Upvotes: 16

renderbox
renderbox

Reputation: 1655

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.

Upvotes: 52

Cat Plus Plus
Cat Plus Plus

Reputation: 130004

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.

Upvotes: 510

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