ModelForm

ModelForm auto-generates form fields from your model’s columns and handles save() for you.

Basic usage

class PostForm(ModelForm):
    class Meta:
        model  = Post
        fields = ["title", "slug", "content", "is_published"]

fields controls which columns become form fields. Use "__all__" to include every column (except id).

Excluding fields

class PostForm(ModelForm):
    class Meta:
        model   = Post
        exclude = ["created_at", "updated_at"]

Overriding auto-generated fields

Declare a field explicitly to override the auto-generated one:

class PostForm(ModelForm):
    title = CharField(max_length=200, label="Post Title", help_text="Keep it concise.")

    class Meta:
        model  = Post
        fields = ["title", "slug", "content"]

Column → field type mapping

SQLAlchemy type	Form field
String	CharField
Text	TextField
Integer	IntegerField
Float	FloatField
Numeric	DecimalField
Boolean	BooleanField
Date	DateField
DateTime	DateTimeField

Create a new object

form = PostForm(data=dict(await request.form()))
if await form.is_valid():
    post = await form.save()     # creates a new Post in the database

Update an existing object

Pass instance to pre-fill the form and update instead of create:

post = await Post.objects.get(id=pk)

# GET — display pre-filled form
form = PostForm(instance=post)

# POST — validate and save
form = PostForm(data=dict(await request.form()), instance=post)
if await form.is_valid():
    await form.save()   # updates existing post

Save without committing

if await form.is_valid():
    post = await form.save(commit=False)
    post.author_id = request.user.id   # set extra fields
    await post.save()

HTML rendering

Render a form directly to HTML without writing a template loop:

form = PostForm()

form.as_p()       # each field wrapped in <p>
form.as_table()   # each field as a <tr> (wrap in <table> yourself)
form.as_div()     # each field in <div class="form-group">

Each method emits labels, widgets, and inline error lists. Useful for quick prototypes or email bodies; use a custom template loop for full control over markup.