ormar/docs/queries/pagination-and-rows-number.md

#Pagination and rows number

Following methods allow you to paginate and limit number of rows in queries.

• paginate(page: int) -> QuerySet

• limit(limit_count: int) -> QuerySet

• offset(offset: int) -> QuerySet

• get() -> Model

• first() -> Model

• QuerysetProxy

  • QuerysetProxy.paginate(page: int) method
  • QuerysetProxy.limit(limit_count: int) method
  • QuerysetProxy.offset(offset: int) method

paginate

paginate(page: int, page_size: int = 20) -> QuerySet

Combines the offset and limit methods based on page number and size

class Track(ormar.Model):
    class Meta:
        tablename = "track"
        metadata = metadata
        database = database

    id: int = ormar.Integer(primary_key=True)
    album: Optional[Album] = ormar.ForeignKey(Album)
    name: str = ormar.String(max_length=100)
    position: int = ormar.Integer()

tracks = await Track.objects.paginate(3).all()
# will return 20 tracks starting at row 41 
# (with default page size of 20)

Note that paginate(2) is equivalent to offset(20).limit(20)

limit

limit(limit_count: int, limit_raw_sql: bool = None) -> QuerySet

You can limit the results to desired number of parent models.

To limit the actual number of database query rows instead of number of main models use the limit_raw_sql parameter flag, and set it to True.

class Track(ormar.Model):
    class Meta:
        tablename = "track"
        metadata = metadata
        database = database

    id: int = ormar.Integer(primary_key=True)
    album: Optional[Album] = ormar.ForeignKey(Album)
    name: str = ormar.String(max_length=100)
    position: int = ormar.Integer()

tracks = await Track.objects.limit(1).all()
# will return just one Track

!!!note All methods that do not return the rows explicitly returns a QuerySet instance so you can chain them together

So operations like `filter()`, `select_related()`, `limit()` and `offset()` etc. can be chained.

Something like `Track.object.select_related("album").filter(album__name="Malibu").offset(1).limit(1).all()`

offset

offset(offset: int, limit_raw_sql: bool = None) -> QuerySet

You can also offset the results by desired number of main models.

To offset the actual number of database query rows instead of number of main models use the limit_raw_sql parameter flag, and set it to True.

class Track(ormar.Model):
    class Meta:
        tablename = "track"
        metadata = metadata
        database = database

    id: int = ormar.Integer(primary_key=True)
    album: Optional[Album] = ormar.ForeignKey(Album)
    name: str = ormar.String(max_length=100)
    position: int = ormar.Integer()

tracks = await Track.objects.offset(1).limit(1).all()
# will return just one Track, but this time the second one

!!!note All methods that do not return the rows explicitly returns a QuerySet instance so you can chain them together

So operations like `filter()`, `select_related()`, `limit()` and `offset()` etc. can be chained.

Something like `Track.object.select_related("album").filter(album__name="Malibu").offset(1).limit(1).all()`

get

get(**kwargs) -> Model

Get's the first row from the db meeting the criteria set by kwargs.

If no criteria is set it will return the last row in db sorted by pk. (The criteria cannot be set also with filter/exclude).

!!!tip To read more about get visit read/get

first

first() -> Model

Gets the first row from the db ordered by primary key column ascending.

!!!tip To read more about first visit read/first

QuerysetProxy methods

When access directly the related ManyToMany field as well as ReverseForeignKey returns the list of related models.

But at the same time it exposes subset of QuerySet API, so you can filter, create, select related etc related models directly from parent model.

paginate

Works exactly the same as paginate function above but allows you to paginate related objects from other side of the relation.

!!!tip To read more about QuerysetProxy visit querysetproxy section

limit

Works exactly the same as limit function above but allows you to paginate related objects from other side of the relation.

!!!tip To read more about QuerysetProxy visit querysetproxy section

offset

Works exactly the same as offset function above but allows you to paginate related objects from other side of the relation.

!!!tip To read more about QuerysetProxy visit querysetproxy section