Django ORM cheat sheet

djangoORM.md

Django ORM Cheat Sheet

Querying Data

Retrieving Objects

• Model.objects.all(): Retrieve all objects in the model.
• Model.objects.get(): Retrieve a single object that matches the query.
• Model.objects.filter(): Retrieve objects that match the specified lookup parameters.
• Model.objects.exclude(): Retrieve objects that do not match the specified lookup parameters.

Chaining Querysets

• filter().exclude(): Chain filters and exclusions together.
• filter().filter(): Chain multiple filters together.
• annotate(): Add annotations to the queryset.
• order_by(): Sort the queryset based on specified fields.
• values(): Return a QuerySet of dictionaries instead of model instances.
• distinct(): Return distinct results for a queryset.

Field Lookups

• exact, iexact: Exact match (case-sensitive, case-insensitive).
• contains, icontains: Case-sensitive, case-insensitive containment test.
• ... (other field lookups)

Modifying Data

Creating Objects

• Model.objects.create(): Create a new object and save it to the database.
• object.save(): Save changes to an existing object.

Updating Objects

• object.save(): Save changes to an existing object.
• Model.objects.update(): Update multiple objects at once.
• update_or_create(): Update an existing object or create a new one.

Deleting Objects

• object.delete(): Delete a single object.
• Model.objects.filter().delete(): Delete multiple objects matching a filter.

Aggregation

• aggregate(): Perform aggregate functions on a queryset (e.g., Sum, Count, Avg).

Relationships

• Access related objects through object attributes (related_name, related_query_name).
• Use double underscores for traversing relationships in queries (e.g., related_model__field).