---
title: "Fungsi Basisdata Geografis"
version: 2.0
locale: id
source: https://docs.djangoproject.com/id/2.0/ref/contrib/gis/functions/
canonical: https://djangodocs.dev/id/2.0/ref/contrib/gis/functions/
---
# Fungsi Basisdata Geografis

The functions documented on this page allow users to access geographic database
functions to be used in annotations, aggregations, or filters in Django.

Contoh:

```
>>> from django.contrib.gis.db.models.functions import Length
>>> Track.objects.annotate(length=Length('line')).filter(length__gt=100)
```

Not all backends support all functions, so refer to the documentation of each
function to see if your database backend supports the function you want to use.
If you call a geographic function on a backend that doesn't support it, you'll
get a `NotImplementedError` exception.

Ringkasan fungsi:

| Pengukuran | Hubungan | Operasi | Penyunting | Bentuk keluaran | Bermacam-macam |
| --- | --- | --- | --- | --- | --- |
| [`Area`](#django.contrib.gis.db.models.functions.Area) | [`Azimuth`](#django.contrib.gis.db.models.functions.Azimuth) | [`Difference`](#django.contrib.gis.db.models.functions.Difference) | [`ForceRHR`](#django.contrib.gis.db.models.functions.ForceRHR) | [`AsGeoJSON`](#django.contrib.gis.db.models.functions.AsGeoJSON) | [`IsValid`](#django.contrib.gis.db.models.functions.IsValid) |
| [`Distance`](#django.contrib.gis.db.models.functions.Distance) | [`BoundingCircle`](#django.contrib.gis.db.models.functions.BoundingCircle) | [`Intersection`](#django.contrib.gis.db.models.functions.Intersection) | [`MakeValid`](#django.contrib.gis.db.models.functions.MakeValid) | [`AsGML`](#django.contrib.gis.db.models.functions.AsGML) | [`MemSize`](#django.contrib.gis.db.models.functions.MemSize) |
| [`Length`](#django.contrib.gis.db.models.functions.Length) | [`Centroid`](#django.contrib.gis.db.models.functions.Centroid) | [`SymDifference`](#django.contrib.gis.db.models.functions.SymDifference) | [`Reverse`](#django.contrib.gis.db.models.functions.Reverse) | [`AsKML`](#django.contrib.gis.db.models.functions.AsKML) | [`NumGeometries`](#django.contrib.gis.db.models.functions.NumGeometries) |
| [`Perimeter`](#django.contrib.gis.db.models.functions.Perimeter) | [`Envelope`](#django.contrib.gis.db.models.functions.Envelope) | [`Union`](#django.contrib.gis.db.models.functions.Union) | [`Scale`](#django.contrib.gis.db.models.functions.Scale) | [`AsSVG`](#django.contrib.gis.db.models.functions.AsSVG) | [`NumPoints`](#django.contrib.gis.db.models.functions.NumPoints) |
|  | [`LineLocatePoint`](#django.contrib.gis.db.models.functions.LineLocatePoint) |  | [`SnapToGrid`](#django.contrib.gis.db.models.functions.SnapToGrid) | [`GeoHash`](#django.contrib.gis.db.models.functions.GeoHash) |  |
|  | [`PointOnSurface`](#django.contrib.gis.db.models.functions.PointOnSurface) |  | [`Transform`](#django.contrib.gis.db.models.functions.Transform) |  |  |
|  |  |  | [`Translate`](#django.contrib.gis.db.models.functions.Translate) |  |  |

## `Area`

#### `class Area(expression, **extra)`

*Tersedia*: MySQL, Oracle, [PostGIS](https://postgis.net/docs/ST_Area.html), SpatiaLite

Accepts a single geographic field or expression and returns the area of the
field as an [`Area`](/id/2.0/ref/contrib/gis/measure/#django.contrib.gis.measure.Area) measure.

MySQL and SpatiaLite without LWGEOM don't support area calculations on
geographic SRSes.

> **Changed in Django 1.11**
>
> Dalam versi terlama, nilai mentah dikembalikan pada MySQL ketika digunakan pada SRS yang diproyeksikan.

## `AsGeoJSON`

#### `class AsGeoJSON(expression, bbox=False, crs=False, precision=8, **extra)`

*Ketersediaan*: MySQL (≥ 5.7.5), [PostGIS](https://postgis.net/docs/ST_AsGeoJSON.html), SpatiaLite

Accepts a single geographic field or expression and returns a [GeoJSON](http://geojson.org/) representation of the geometry. Note that the result is
not a complete GeoJSON structure but only the `geometry` key content of a
GeoJSON structure. See also [Penserial GeoJSON](/id/2.0/ref/contrib/gis/serializers/).

Contoh:

```
>>> City.objects.annotate(json=AsGeoJSON('point')).get(name='Chicago').json
{"type":"Point","coordinates":[-87.65018,41.85039]}
```

| Argumen Katakunci | Deskripsi |
| --- | --- |
| `bbox` | Setel ini menjadi `True` jika anda ingin membatasi kotak untuk disertakan dalam GeoJSON yang dikembalikan. |
| `crs` | Setel ini menjadi `True` jika anda ingin sistem acuan kordinat disertakan dalam kembalian GeoJSON. Abaikan pada MySQL. |
| `ketelitian` | Itu mungkin digunakan untuk menentikan sejumlah angka penting untuk kordinat dalam perwakilan GeoJSON -- nilai awalan adalah 8. |

> **Changed in Django 2.0**
>
> Dukungan MySQL telah ditambahkan.

## `AsGML`

#### `class AsGML(expression, version=2, precision=8, **extra)`

*Tersedia*: Oracle, [PostGIS](https://postgis.net/docs/ST_AsGML.html), SpatiaLite

Menerima bidang geografis tunggal atau pernyataan dan mengembalikan perwakilan [Geographic Markup Language (GML)](https://en.wikipedia.org/wiki/Geography_Markup_Language) dari geometri.

Contoh:

```
>>> qs = Zipcode.objects.annotate(gml=AsGML('poly'))
>>> print(qs[0].gml)
<gml:Polygon srsName="EPSG:4326"><gml:OuterBoundaryIs>-147.78711,70.245363 ...
-147.78711,70.245363</gml:OuterBoundaryIs></gml:Polygon>
```

| Argumen Katakunci | Deskripsi |
| --- | --- |
| `ketelitian` | Menentukan sejumlah angka penting untuk kordinat dalam perwakilan GML -- nilai awalan adalah 8. Abaikan pada Oracle. |
| `versi` | Menentukan versi GML untuk menggunakan: 2 (awalan) atau 3. |

> **Changed in Django 1.11**
>
> Dukungan Oracle telah ditambahkan.

## `AsKML`

#### `class AsKML(expression, precision=8, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_AsKML.html), SpatiaLite

Menerima bidang geografis tunggal atau pernyataan dan mengembalikan perwakilan [Keyhole Markup Language (KML)](https://developers.google.com/kml/documentation/) dari geometri.

Contoh:

```
>>> qs = Zipcode.objects.annotate(kml=AsKML('poly'))
>>> print(qs[0].kml)
<Polygon><outerBoundaryIs><LinearRing><coordinates>-103.04135,36.217596,0 ...
-103.04135,36.217596,0</coordinates></LinearRing></outerBoundaryIs></Polygon>
```

| Argumen Katakunci | Deskripsi |
| --- | --- |
| `ketelitian` | Katakunci ini mungkin digunakan untuk menentukan sejumlah angka penting untuk kordinat dalam perwakilan KML -- nilai awalan adalah 8. |

## `AsSVG`

#### `class AsSVG(expression, relative=False, precision=8, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_AsSVG.html), SpatiaLite

Menerima bidang geografis tunggal atau pernyataan dan mengembalikan sebuah perwakilan [Scalable Vector Graphics (SVG)](https://www.w3.org/Graphics/SVG/) dari geometri.

| Argumen Katakunci | Deskripsi |
| --- | --- |
| `relative` | Jika disetel ke `True`, jalur data akan diterapkan dalam ketentuan dari pergerakan relatif. Awalan menjadi False11, berarti bahwa perpindahan mutlak digunakan sebagai gantinya. |
| `ketelitian` | Katakunci mungkin digunakan untuk menentukan sejumlah angka penting untuk kordinat dalam perwakilan SVG -- nilai awalan adalah 8. |

## `Azimuth`

#### `class Azimuth(point_a, point_b, **extra)`

> **New in Django 2.0**

*Ketersediaan*: [PostGIS](https://postgis.net/docs/ST_Azimuth.html), SpatiaLite (LWGEOM)

Returns the azimuth in radians of the segment defined by the given point
geometries, or `None` if the two points are coincident. The azimuth is angle
referenced from north and is positive clockwise: north = `0`; east = `π/2`;
south = `π`; west = `3π/2`.

## `BoundingCircle`

#### `class BoundingCircle(expression, num_seg=48, **extra)`

*Ketersediaan*: [PostGIS](https://postgis.net/docs/ST_MinimumBoundingCircle.html), [Oracle](https://docs.oracle.com/database/121/SPATL/sdo_geom-sdo_mbc.htm#SPATL1554)

Accepts a single geographic field or expression and returns the smallest circle
polygon that can fully contain the geometry.

Parameter `num_seg` hanya digunakan pada PostGIS.

> **Changed in Django 1.11**
>
> Dukungan Oracle telah ditambahkan.

## `Centroid`

#### `class Centroid(expression, **extra)`

*Tersedia*: MySQL, [PostGIS](https://postgis.net/docs/ST_Centroid.html), Oracle, SpatiaLite

Menerima bidang geografis tunggal atau mengembalikan nilai `centroid` dari geometri.

## `Difference`

#### `class Difference(expr1, expr2, **extra)`

*Tersedia*: MySQL (≥ 5.6.1), [PostGIS](https://postgis.net/docs/ST_Difference.html), Oracle, SpatiaLite

Menerima dua bidang geografis atau pernyataan dan mengembalikan perbedaan geometri, yaitu bagian dari geometri A yang tidak berinteraksi dengan geometri B.

## `Distance`

#### `class Distance(expr1, expr2, spheroid=None, **extra)`

*Tersedia*: MySQL (≥ 5.6.1), [PostGIS](https://postgis.net/docs/ST_Distance.html), Oracle, SpatiaLite

Accepts two geographic fields or expressions and returns the distance between
them, as a [`Distance`](/id/2.0/ref/contrib/gis/measure/#django.contrib.gis.measure.Distance) object. On MySQL, a raw
float value is returned when the coordinates are geodetic.

On backends that support distance calculation on geodetic coordinates, the
proper backend function is automatically chosen depending on the SRID value of
the geometries (e.g. [ST\_DistanceSphere](https://postgis.net/docs/ST_DistanceSphere.html) on PostGIS).

Ketika jarak dihitung dengan kordinat (bersiku-siku) geodetic, seperti halnya dengan awalan SRID WGS84 (4326), anda dapat menyetel argumen kata kunci `spheroid` untuk memutuskan jika perhitungan harus berdasarkan pada bulatan sederhana (kurang akurat, kurang sumber daya-intensif) atau pada sebuah berbentuk bola (lebih akurat, lebih sumber daya-intensif)

In the following example, the distance from the city of Hobart to every other
[`PointField`](/id/2.0/ref/contrib/gis/model-api/#django.contrib.gis.db.models.PointField) in the `AustraliaCity`
queryset is calculated:

```
>>> from django.contrib.gis.db.models.functions import Distance
>>> pnt = AustraliaCity.objects.get(name='Hobart').point
>>> for city in AustraliaCity.objects.annotate(distance=Distance('point', pnt)):
...     print(city.name, city.distance)
Wollongong 990071.220408 m
Shellharbour 972804.613941 m
Thirroul 1002334.36351 m
...
```

> **Note**
>
> Because the `distance` attribute is a
> [`Distance`](/id/2.0/ref/contrib/gis/measure/#django.contrib.gis.measure.Distance) object, you can easily express
> the value in the units of your choice. For example, `city.distance.mi` is
> the distance value in miles and `city.distance.km` is the distance value
> in kilometers. See [Obyek Pengukuran](/id/2.0/ref/contrib/gis/measure/) for usage details and the list of
> [Satuan Didukung](/id/2.0/ref/contrib/gis/measure/#supported-units).

> **Changed in Django 1.11**
>
> Dalam versi terlama, nilai mentah dikembalikan pada MySQL ketika digunakan pada SRS yang diproyeksikan.

## `Envelope`

#### `class Envelope(expression, **extra)`

*Tersedia*: MySQL, [PostGIS](https://postgis.net/docs/ST_Envelope.html), SpatiaLite

Accepts a single geographic field or expression and returns the geometry
representing the bounding box of the geometry.

## `ForceRHR`

#### `class ForceRHR(expression, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_ForceRHR.html)

Accepts a single geographic field or expression and returns a modified version
of the polygon/multipolygon in which all of the vertices follow the
right-hand rule.

## `GeoHash`

#### `class GeoHash(expression, precision=None, **extra)`

*Ketersediaan*: MySQL (≥ 5.7.5), [PostGIS](https://postgis.net/docs/ST_GeoHash.html), SpatiaLite (LWGEOM)

Menerima bidang geografi tunggal atau pernyataan dan mengembalikan perwakilan [GeoHash](https://en.wikipedia.org/wiki/Geohash) dari geometri.

Argumen kata kunci `precision` mengendalikan sejumlah karakter dalam hasilnya.

> **Changed in Django 2.0**
>
> Dukungan MySQL telah ditambahkan.

## `Intersection`

#### `class Intersection(expr1, expr2, **extra)`

*Tersedia*: MySQL (≥ 5.6.1), [PostGIS](https://postgis.net/docs/ST_Intersection.html), Oracle, SpatiaLite

Menerima dua bidang geografi dan pernyataan dan mengembalikan persimpangan geometri diantara mereka.

## `IsValid`

#### `class IsValid(expr)`

*Ketersediaan*: MySQL (≥ 5.7.5), [PostGIS](https://postgis.net/docs/ST_IsValid.html), Oracle, SpatiaLite (LWGEOM)

Menerima sebuah bidang geografi atau pernyataan dan percobaan jika nilai berbentuk bagus. Mengembalikan `True` jika nilainya adalah geometri sah dan `False` sebaliknya.

> **Changed in Django 1.11**
>
> Dukungan SpatiaLite dan Oracle telah ditambahkan.

> **Changed in Django 2.0**
>
> Dukungan MySQL telah ditambahkan.

## `Length`

#### `class Length(expression, spheroid=True, **extra)`

*Tersedia*: MySQL, Oracle, [PostGIS](https://postgis.net/docs/ST_Length.html), SpatiaLite

Accepts a single geographic linestring or multilinestring field or expression
and returns its length as a [`Distance`](/id/2.0/ref/contrib/gis/measure/#django.contrib.gis.measure.Distance)
measure.

On PostGIS and SpatiaLite, when the coordinates are geodetic (angular), you can
specify if the calculation should be based on a simple sphere (less
accurate, less resource-intensive) or on a spheroid (more accurate, more
resource-intensive) with the `spheroid` keyword argument.

MySQL tidak mendukung dukungan perhitungan panjang pada geografis SRS.

> **Changed in Django 1.11**
>
> Dalam versi terlama, nilai mentah dikembalikan pada MySQL.

## `LineLocatePoint`

#### `class LineLocatePoint(linestring, point, **extra)`

> **New in Django 2.0**

*Ketersediaan*: [PostGIS](https://postgis.net/docs/ST_LineLocatePoint.html), SpatiaLite

Returns a float between 0 and 1 representing the location of the closest point on
`linestring` to the given `point`, as a fraction of the 2D line length.

## `MakeValid`

#### `class MakeValid(expr)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_MakeValid.html), SpatiaLite (LWGEOM)

Accepts a geographic field or expression and attempts to convert the value into
a valid geometry without losing any of the input vertices. Geometries that are
already valid are returned without changes. Simple polygons might become a
multipolygon and the result might be of lower dimension than the input.

> **Changed in Django 1.11**
>
> Dukungan SpatiaLite  telah ditambahkan.

## `MemSize`

#### `class MemSize(expression, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_MemSize.html)

Accepts a single geographic field or expression and returns the memory size
(number of bytes) that the geometry field takes.

## `NumGeometries`

#### `class NumGeometries(expression, **extra)`

*Tersedia*: MySQL, [PostGIS](https://postgis.net/docs/ST_NumGeometries.html), Oracle, SpatiaLite

Accepts a single geographic field or expression and returns the number of
geometries if the geometry field is a collection (e.g., a `GEOMETRYCOLLECTION`
or `MULTI*` field). Returns 1 for single geometries.

Pada MySQL, mengembalikan `None` untuk geometri tunggal.

## `NumPoints`

#### `class NumPoints(expression, **extra)`

*Tersedia*: MySQL, [PostGIS](https://postgis.net/docs/ST_NPoints.html), Oracle, SpatiaLite

Accepts a single geographic field or expression and returns the number of points
in a geometry.

Pada MySQL, mengembalikan `None` untuk geometri bukan-`LINESTRING` apapun.

> **Changed in Django 1.11**
>
> SpatiaLite mendukung untuk geometri bukan-`LINESTRING` telah ditambahkan.

## `Perimeter`

#### `class Perimeter(expression, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_Perimeter.html), Oracle, SpatiaLite

Accepts a single geographic field or expression and returns the perimeter of the
geometry field as a [`Distance`](/id/2.0/ref/contrib/gis/measure/#django.contrib.gis.measure.Distance) object.

## `PointOnSurface`

#### `class PointOnSurface(expression, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_PointOnSurface.html), Oracle, SpatiaLite

Accepts a single geographic field or expression and returns a `Point` geometry
guaranteed to lie on the surface of the field; otherwise returns `None`.

## `Reverse`

#### `class Reverse(expression, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_Reverse.html), Oracle, SpatiaLite

Accepts a single geographic field or expression and returns a geometry with
reversed coordinates.

## `Scale`

#### `class Scale(expression, x, y, z=0.0, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_Scale.html), SpatiaLite

Accepts a single geographic field or expression and returns a geometry with
scaled coordinates by multiplying them with the `x`, `y`, and optionally
`z` parameters.

## `SnapToGrid`

#### `class SnapToGrid(expression, *args, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_SnapToGrid.html), SpatiaLite

Accepts a single geographic field or expression and returns a geometry with all
points snapped to the given grid.  How the geometry is snapped to the grid
depends on how many numeric (either float, integer, or long) arguments are
given.

| Jumlah Argumen | Deskripsi |
| --- | --- |
| 1 | A single size to snap both the X and Y grids to. |
| 2 | X and Y sizes to snap the grid to. |
| 4 | X, Y sizes and the corresponding X, Y origins. |

## `SymDifference`

#### `class SymDifference(expr1, expr2, **extra)`

*Tersedia*: MySQL (≥ 5.6.1), [PostGIS](https://postgis.net/docs/ST_SymDifference.html), Oracle, SpatiaLite

Accepts two geographic fields or expressions and returns the geometric
symmetric difference (union without the intersection) between the given
parameters.

## `Transform`

#### `class Transform(expression, srid, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_Transform.html), Oracle, SpatiaLite

Accepts a geographic field or expression and a SRID integer code, and returns
the transformed geometry to the spatial reference system specified by the
`srid` parameter.

> **Note**
>
> What spatial reference system an integer SRID corresponds to may depend on
> the spatial database used.  In other words, the SRID numbers used for Oracle
> are not necessarily the same as those used by PostGIS.

## `Translate`

#### `class Translate(expression, x, y, z=0.0, **extra)`

*Tersedia*: [PostGIS](https://postgis.net/docs/ST_Translate.html), SpatiaLite

Accepts a single geographic field or expression and returns a geometry with
its coordinates offset by the `x`, `y`, and optionally `z` numeric
parameters.

## `Union`

#### `class Union(expr1, expr2, **extra)`

*Tersedia*: MySQL (≥ 5.6.1), [PostGIS](https://postgis.net/docs/ST_Union.html), Oracle, SpatiaLite

Menerima dua bidang geografi atau pernyataan dan mengembalikan gabungan dari kedua geometri.