# Τεκμηρίωση του Django - 1.10.7

# GeoQuerySet API Reference

class `GeoQuerySet`(model=None)

## Spatial Lookups

The spatial lookups in this section are available for `GeometryField` and `RasterField`.

For an introduction, see the spatial lookups introduction. For an overview of what lookups are compatible with a particular spatial backend, refer to the spatial lookup compatibility table.

Spatial lookups now support raster input.

### Lookups with rasters

All examples in the reference below are given for geometry fields and inputs, but the lookups can be used the same way with rasters on both sides. Whenever a lookup doesn’t support raster input, the input is automatically converted to a geometry where necessary using the ST_Polygon function. See also the introduction to raster lookups.

The database operators used by the lookups can be divided into three categories:

- Native raster support `N`: the operator accepts rasters natively on both sides of the lookup, and raster input can be mixed with geometry inputs.
- Bilateral raster support `B`: the operator supports rasters only if both sides of the lookup receive raster inputs. Raster data is automatically converted to geometries for mixed lookups.
- Geometry conversion support `C`. The lookup does not have native raster support, all raster data is automatically converted to geometries.

The examples below show the SQL equivalent for the lookups in the different types of raster support. The same pattern applies to all spatial lookups.

Case | Lookup | SQL Equivalent
--- | --- | ---
N, B | `rast__contains=rst` | `ST_Contains(rast, rst)`
N, B | `rast__1__contains=(rst, 2)` | `ST_Contains(rast, 1, rst, 2)`
B, C | `rast__contains=geom` | `ST_Contains(ST_Polygon(rast), geom)`
B, C | `rast__1__contains=geom` | `ST_Contains(ST_Polygon(rast, 1), geom)`
B, C | `poly__contains=rst` | `ST_Contains(poly, ST_Polygon(rst))`
B, C | `poly__contains=(rst, 1)` | `ST_Contains(poly, ST_Polygon(rst, 1))`
C | `rast__crosses=rst` | `ST_Crosses(ST_Polygon(rast), ST_Polygon(rst))`
C | `rast__1__crosses=(rst, 2)` | `ST_Crosses(ST_Polygon(rast, 1), ST_Polygon(rst, 2))`
C | `rast__crosses=geom` | `ST_Crosses(ST_Polygon(rast), geom)`
C | `poly__crosses=rst` | `ST_Crosses(poly, ST_Polygon(rst))`

Spatial lookups with rasters are only supported for PostGIS backends (denominated as PGRaster in this section).

### `bbcontains`

Availability: PostGIS, MySQL, SpatiaLite, PGRaster (Native)

Tests if the geometry or raster field’s bounding box completely contains the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__bbcontains=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `poly ~ geom`
MySQL | `MBRContains(poly, geom)`
SpatiaLite | `MbrContains(poly, geom)`

### `bboverlaps`

Availability: PostGIS, MySQL, SpatiaLite, PGRaster (Native)

Tests if the geometry field’s bounding box overlaps the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__bboverlaps=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `poly && geom`
MySQL | `MBROverlaps(poly, geom)`
SpatiaLite | `MbrOverlaps(poly, geom)`

### `contained`

Availability: PostGIS, MySQL, SpatiaLite, PGRaster (Native)

Tests if the geometry field’s bounding box is completely contained by the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__contained=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `poly @ geom`
MySQL | `MBRWithin(poly, geom)`
SpatiaLite | `MbrWithin(poly, geom)`

### `contains`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

Tests if the geometry field spatially contains the lookup geometry.

Example:

    Zipcode.objects.filter(poly__contains=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Contains(poly, geom)`
Oracle | `SDO_CONTAINS(poly, geom)`
MySQL | `MBRContains(poly, geom)`
SpatiaLite | `Contains(poly, geom)`

### `contains_properly`

Availability: PostGIS, PGRaster (Bilateral)

Returns true if the lookup geometry intersects the interior of the geometry field, but not the boundary (or exterior). [4]

Example:

    Zipcode.objects.filter(poly__contains_properly=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_ContainsProperly(poly, geom)`

### `coveredby`

Availability: PostGIS, Oracle, PGRaster (Bilateral)

Tests if no point in the geometry field is outside the lookup geometry. [3]

Example:

    Zipcode.objects.filter(poly__coveredby=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_CoveredBy(poly, geom)`
Oracle | `SDO_COVEREDBY(poly, geom)`

### `covers`

Availability: PostGIS, Oracle, PGRaster (Bilateral)

Tests if no point in the lookup geometry is outside the geometry field. [3]

Example:

    Zipcode.objects.filter(poly__covers=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Covers(poly, geom)`
Oracle | `SDO_COVERS(poly, geom)`

### `crosses`

Availability: PostGIS, SpatiaLite, PGRaster (Conversion)

Tests if the geometry field spatially crosses the lookup geometry.

Example:

    Zipcode.objects.filter(poly__crosses=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Crosses(poly, geom)`
SpatiaLite | `Crosses(poly, geom)`

### `disjoint`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

Tests if the geometry field is spatially disjoint from the lookup geometry.

Example:

    Zipcode.objects.filter(poly__disjoint=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Disjoint(poly, geom)`
Oracle | `SDO_GEOM.RELATE(poly, 'DISJOINT', geom, 0.05)`
MySQL | `MBRDisjoint(poly, geom)`
SpatiaLite | `Disjoint(poly, geom)`

### `equals`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Conversion)

### `exact`, `same_as`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

### `intersects`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

Tests if the geometry field spatially intersects the lookup geometry.

Example:

    Zipcode.objects.filter(poly__intersects=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Intersects(poly, geom)`
Oracle | `SDO_OVERLAPBDYINTERSECT(poly, geom)`
MySQL | `MBRIntersects(poly, geom)`
SpatiaLite | `Intersects(poly, geom)`

### `isvalid`

Availability: PostGIS

Tests if the geometry is valid.

Example:

    Zipcode.objects.filter(poly__isvalid=True)

PostGIS equivalent:

    SELECT ... WHERE ST_IsValid(poly)

### `overlaps`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

### `relate`

Availability: PostGIS, Oracle, SpatiaLite, PGRaster (Conversion)

Tests if the geometry field is spatially related to the lookup geometry by the values given in the given pattern. This lookup requires a tuple parameter, `(geom, pattern)`; the form of `pattern` will depend on the spatial backend:

#### PostGIS & SpatiaLite

On these spatial backends the intersection pattern is a string comprising nine characters, which define intersections between the interior, boundary, and exterior of the geometry field and the lookup geometry. The intersection pattern matrix may only use the following characters: `1`, `2`, `T`, `F`, or `*`. This lookup type allows users to “fine tune” a specific geometric relationship consistent with the DE-9IM model. [1]

Geometry example:

    # A tuple lookup parameter is used to specify the geometry and
    # the intersection pattern (the pattern here is for 'contains').
    Zipcode.objects.filter(poly__relate=(geom, 'T*T***FF*'))

PostGIS SQL equivalent:

    SELECT ... WHERE ST_Relate(poly, geom, 'T*T***FF*')

SpatiaLite SQL equivalent:

    SELECT ... WHERE Relate(poly, geom, 'T*T***FF*')

Raster example:

    Zipcode.objects.filter(poly__relate=(rast, 1, 'T*T***FF*'))
    Zipcode.objects.filter(rast__2__relate=(rast, 1, 'T*T***FF*'))

PostGIS SQL equivalent:

    SELECT ... WHERE ST_Relate(poly, ST_Polygon(rast, 1), 'T*T***FF*')
    SELECT ... WHERE ST_Relate(ST_Polygon(rast, 2), ST_Polygon(rast, 1), 'T*T***FF*')

#### Oracle

Here the relation pattern is comprised of at least one of the nine relation strings: `TOUCH`, `OVERLAPBDYDISJOINT`, `OVERLAPBDYINTERSECT`, `EQUAL`, `INSIDE`, `COVEREDBY`, `CONTAINS`, `COVERS`, `ON`, and `ANYINTERACT`. Multiple strings may be combined with the logical Boolean operator OR, for example, `'inside+touch'`. [2] The relation strings are case-insensitive.

Example:

    Zipcode.objects.filter(poly__relate=(geom, 'anyinteract'))

Oracle SQL equivalent:

    SELECT ... WHERE SDO_RELATE(poly, geom, 'anyinteract')

### `touches`

Availability: PostGIS, Oracle, MySQL, SpatiaLite

Tests if the geometry field spatially touches the lookup geometry.

Example:

    Zipcode.objects.filter(poly__touches=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Touches(poly, geom)`
MySQL | `MBRTouches(poly, geom)`
Oracle | `SDO_TOUCH(poly, geom)`
SpatiaLite | `Touches(poly, geom)`

### `within`

Availability: PostGIS, Oracle, MySQL, SpatiaLite, PGRaster (Bilateral)

Tests if the geometry field is spatially within the lookup geometry.

Example:

    Zipcode.objects.filter(poly__within=geom)

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Within(poly, geom)`
MySQL | `MBRWithin(poly, geom)`
Oracle | `SDO_INSIDE(poly, geom)`
SpatiaLite | `Within(poly, geom)`

### `left`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box is strictly to the left of the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__left=geom)

PostGIS equivalent:

    SELECT ... WHERE poly << geom

### `right`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box is strictly to the right of the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__right=geom)

PostGIS equivalent:

    SELECT ... WHERE poly >> geom

### `overlaps_left`

Availability: PostGIS, PGRaster (Bilateral)

Tests if the geometry field’s bounding box overlaps or is to the left of the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__overlaps_left=geom)

PostGIS equivalent:

    SELECT ... WHERE poly &< geom

### `overlaps_right`

Availability: PostGIS, PGRaster (Bilateral)

Tests if the geometry field’s bounding box overlaps or is to the right of the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__overlaps_right=geom)

PostGIS equivalent:

    SELECT ... WHERE poly &> geom

### `overlaps_above`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box overlaps or is above the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__overlaps_above=geom)

PostGIS equivalent:

    SELECT ... WHERE poly |&> geom

### `overlaps_below`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box overlaps or is below the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__overlaps_below=geom)

PostGIS equivalent:

    SELECT ... WHERE poly &<| geom

### `strictly_above`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box is strictly above the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__strictly_above=geom)

PostGIS equivalent:

    SELECT ... WHERE poly |>> geom

### `strictly_below`

Availability: PostGIS, PGRaster (Conversion)

Tests if the geometry field’s bounding box is strictly below the lookup geometry’s bounding box.

Example:

    Zipcode.objects.filter(poly__strictly_below=geom)

PostGIS equivalent:

    SELECT ... WHERE poly <<| geom

## Distance Lookups

Availability: PostGIS, Oracle, SpatiaLite, PGRaster (Native)

For an overview on performing distance queries, please refer to the distance queries introduction.

Distance lookups take the following form:

    <field>__<distance lookup>=(<geometry/raster>, <distance value>[, 'spheroid'])
    <field>__<distance lookup>=(<raster>, <band_index>, <distance value>[, 'spheroid'])
    <field>__<band_index>__<distance lookup>=(<raster>, <band_index>, <distance value>[, 'spheroid'])

The value passed into a distance lookup is a tuple; the first two values are mandatory, and are the geometry to calculate distances to, and a distance value (either a number in units of the field, a `Distance` object, or a query expression <ref/models/expressions>). To pass a band index to the lookup, use a 3-tuple where the second entry is the band index.

With PostGIS, on every distance lookup but `dwithin`, an optional element, `'spheroid'`, may be included to tell GeoDjango to use the more accurate spheroid distance calculation functions on fields with a geodetic coordinate system (e.g., `ST_Distance_Spheroid` would be used instead of `ST_Distance_Sphere`). The simpler `ST_Distance` function is used with projected coordinate systems. Rasters are converted to geometries for spheroid based lookups.

The ability to pass an expression as the distance value was added.

### `distance_gt`

Returns models where the distance to the geometry field from the lookup geometry is greater than the given distance value.

Example:

    Zipcode.objects.filter(poly__distance_gt=(geom, D(m=5)))

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Distance/ST_Distance_Sphere(poly, geom) > 5`
Oracle | `SDO_GEOM.SDO_DISTANCE(poly, geom, 0.05) > 5`
SpatiaLite | `Distance(poly, geom) > 5`

### `distance_gte`

Returns models where the distance to the geometry field from the lookup geometry is greater than or equal to the given distance value.

Example:

    Zipcode.objects.filter(poly__distance_gte=(geom, D(m=5)))

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Distance/ST_Distance_Sphere(poly, geom) >= 5`
Oracle | `SDO_GEOM.SDO_DISTANCE(poly, geom, 0.05) >= 5`
SpatiaLite | `Distance(poly, geom) >= 5`

### `distance_lt`

Returns models where the distance to the geometry field from the lookup geometry is less than the given distance value.

Example:

    Zipcode.objects.filter(poly__distance_lt=(geom, D(m=5)))

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Distance/ST_Distance_Sphere(poly, geom) < 5`
Oracle | `SDO_GEOM.SDO_DISTANCE(poly, geom, 0.05) < 5`
SpatiaLite | `Distance(poly, geom) < 5`

### `distance_lte`

Returns models where the distance to the geometry field from the lookup geometry is less than or equal to the given distance value.

Example:

    Zipcode.objects.filter(poly__distance_lte=(geom, D(m=5)))

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_Distance/ST_Distance_Sphere(poly, geom) <= 5`
Oracle | `SDO_GEOM.SDO_DISTANCE(poly, geom, 0.05) <= 5`
SpatiaLite | `Distance(poly, geom) <= 5`

### `dwithin`

Returns models where the distance to the geometry field from the lookup geometry are within the given distance from one another. Note that you can only provide `Distance` objects if the targeted geometries are in a projected system. For geographic geometries, you should use units of the geometry field (e.g. degrees for `WGS84`) .

Example:

    Zipcode.objects.filter(poly__dwithin=(geom, D(m=5)))

Backend | SQL Equivalent
--- | ---
PostGIS | `ST_DWithin(poly, geom, 5)`
Oracle | `SDO_WITHIN_DISTANCE(poly, geom, 5)`

Σημείωση

This lookup is not available on SpatiaLite.

## `GeoQuerySet` Methods

Αποσύρθηκε στην έκδοση 1.9: Using `GeoQuerySet` methods is now deprecated in favor of the new Geographic Database Functions. Albeit a little more verbose, they are much more powerful in how it is possible to combine them to build more complex queries.

`GeoQuerySet` methods specify that a spatial operation be performed on each spatial operation on each geographic field in the queryset and store its output in a new attribute on the model (which is generally the name of the `GeoQuerySet` method).

There are also aggregate `GeoQuerySet` methods which return a single value instead of a queryset. This section will describe the API and availability of every `GeoQuerySet` method available in GeoDjango.

Σημείωση

What methods are available depend on your spatial backend. See the compatibility table for more details.

With a few exceptions, the following keyword arguments may be used with all `GeoQuerySet` methods:

Keyword Argument | Description
--- | ---
`field_name` | By default, `GeoQuerySet` methods use the first geographic field encountered in the model. This keyword should be used to specify another geographic field (e.g., `field_name='point2'`) when there are multiple geographic fields in a model. On PostGIS, the `field_name` keyword may also be used on geometry fields in models that are related via a `ForeignKey` relation (e.g., `field_name='related__point'`).
`model_att` | By default, `GeoQuerySet` methods typically attach their output in an attribute with the same name as the `GeoQuerySet` method. Setting this keyword with the desired attribute name will override this default behavior. For example, `qs = Zipcode.objects.centroid(model_att='c')` will attach the centroid of the `Zipcode` geometry field in a `c` attribute on every model rather than in a `centroid` attribute. This keyword is required if a method name clashes with an existing `GeoQuerySet` method – if you wanted to use the `area()` method on model with a `PolygonField` named `area`, for example.

### Measurement

Availability: PostGIS, Oracle, SpatiaLite

#### `area`

`GeoQuerySet.``area`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Area` function instead.

Returns the area of the geographic field in an `area` attribute on each element of this GeoQuerySet.

#### `distance`

`GeoQuerySet.``distance`(geom, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Distance` function instead.

This method takes a geometry as a parameter, and attaches a `distance` attribute to every model in the returned queryset that contains the distance (as a `Distance` object) to the given geometry.

In the following example (taken from the GeoDjango distance tests), the distance from the Tasmanian city of Hobart to every other `PointField` in the `AustraliaCity` queryset is calculated:

    >>> pnt = AustraliaCity.objects.get(name='Hobart').point
    >>> for city in AustraliaCity.objects.distance(pnt): print(city.name, city.distance)
    Wollongong 990071.220408 m
    Shellharbour 972804.613941 m
    Thirroul 1002334.36351 m
    Mittagong 975691.632637 m
    Batemans Bay 834342.185561 m
    Canberra 598140.268959 m
    Melbourne 575337.765042 m
    Sydney 1056978.87363 m
    Hobart 0.0 m
    Adelaide 1162031.83522 m
    Hillsdale 1049200.46122 m

Σημείωση

Because the `distance` attribute is a `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 Measurement Objects for usage details and the list of Supported units.

#### `length`

`GeoQuerySet.``length`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Length` function instead.

Returns the length of the geometry field in a `length` attribute (a `Distance` object) on each model in the queryset.

#### `perimeter`

`GeoQuerySet.``perimeter`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Perimeter` function instead.

Returns the perimeter of the geometry field in a `perimeter` attribute (a `Distance` object) on each model in the queryset.

### Geometry Relationships

The following methods take no arguments, and attach geometry objects each element of the `GeoQuerySet` that is the result of relationship function evaluated on the geometry field.

#### `centroid`

`GeoQuerySet.``centroid`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Centroid` function instead.

Availability: PostGIS, Oracle, SpatiaLite

Returns the `centroid` value for the geographic field in a `centroid` attribute on each element of the `GeoQuerySet`.

#### `envelope`

`GeoQuerySet.``envelope`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Envelope` function instead.

Availability: PostGIS, SpatiaLite

Returns a geometry representing the bounding box of the geometry field in an `envelope` attribute on each element of the `GeoQuerySet`.

#### `point_on_surface`

`GeoQuerySet.``point_on_surface`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `PointOnSurface` function instead.

Availability: PostGIS, Oracle, SpatiaLite

Returns a Point geometry guaranteed to lie on the surface of the geometry field in a `point_on_surface` attribute on each element of the queryset; otherwise sets with None.

### Geometry Editors

#### `force_rhr`

`GeoQuerySet.``force_rhr`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `ForceRHR` function instead.

Availability: PostGIS

Returns a modified version of the polygon/multipolygon in which all of the vertices follow the Right-Hand-Rule, and attaches as a `force_rhr` attribute on each element of the queryset.

#### `reverse_geom`

`GeoQuerySet.``reverse_geom`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Reverse` function instead.

Availability: PostGIS, Oracle

Reverse the coordinate order of the geometry field, and attaches as a `reverse` attribute on each element of the queryset.

#### `scale`

`GeoQuerySet.``scale`(x, y, z=0.0, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Scale` function instead.

Availability: PostGIS, SpatiaLite

#### `snap_to_grid`

`GeoQuerySet.``snap_to_grid`(*args, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `SnapToGrid` function instead.

Snap all points of the input geometry to the grid. How the geometry is snapped to the grid depends on how many numeric (either float, integer, or long) arguments are given.

Number of Arguments | Description
--- | ---
1 | A single size to snap bot 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.

#### `transform`

`GeoQuerySet.``transform`(srid=4326, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Transform` function instead.

Availability: PostGIS, Oracle, SpatiaLite

The `transform` method transforms the geometry field of a model to the spatial reference system specified by the `srid` parameter. If no `srid` is given, then 4326 (WGS84) is used by default.

Σημείωση

Unlike other `GeoQuerySet` methods, `transform` stores its output “in-place”. In other words, no new attribute for the transformed geometry is placed on the models.

Σημείωση

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.

Example:

    >>> qs = Zipcode.objects.all().transform() # Transforms to WGS84
    >>> qs = Zipcode.objects.all().transform(32140) # Transforming to "NAD83 / Texas South Central"
    >>> print(qs[0].poly.srid)
    32140
    >>> print(qs[0].poly)
    POLYGON ((234055.1698884720099159 4937796.9232223574072123 ...

#### `translate`

`GeoQuerySet.``translate`(x, y, z=0.0, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `Translate` function instead.

Availability: PostGIS, SpatiaLite

Translates the geometry field to a new location using the given numeric parameters as offsets.

### Geometry Operations

Availability: PostGIS, Oracle, SpatiaLite

The following methods all take a geometry as a parameter and attach a geometry to each element of the `GeoQuerySet` that is the result of the operation.

#### `difference`

`GeoQuerySet.``difference`(geom)

Αποσύρθηκε στην έκδοση 1.9: Use the `Difference` function instead.

Returns the spatial difference of the geographic field with the given geometry in a `difference` attribute on each element of the `GeoQuerySet`.

#### `intersection`

`GeoQuerySet.``intersection`(geom)

Αποσύρθηκε στην έκδοση 1.9: Use the `Intersection` function instead.

Returns the spatial intersection of the geographic field with the given geometry in an `intersection` attribute on each element of the `GeoQuerySet`.

#### `sym_difference`

`GeoQuerySet.``sym_difference`(geom)

Αποσύρθηκε στην έκδοση 1.9: Use the `SymDifference` function instead.

Returns the symmetric difference of the geographic field with the given geometry in a `sym_difference` attribute on each element of the `GeoQuerySet`.

#### `union`

`GeoQuerySet.``union`(geom)

Αποσύρθηκε στην έκδοση 1.9: Use the `Union` function instead.

Returns the union of the geographic field with the given geometry in an `union` attribute on each element of the `GeoQuerySet`.

### Geometry Output

The following `GeoQuerySet` methods will return an attribute that has the value of the geometry field in each model converted to the requested output format.

#### `geohash`

`GeoQuerySet.``geohash`(precision=20, **kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `GeoHash` function instead.

Attaches a `geohash` attribute to every model the queryset containing the GeoHash representation of the geometry.

#### `geojson`

`GeoQuerySet.``geojson`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `AsGeoJSON` function instead.

Availability: PostGIS, SpatiaLite

Attaches a `geojson` attribute to every model in the queryset that contains the GeoJSON representation of the geometry.

Keyword Argument | Description
--- | ---
`precision` | It may be used to specify the number of significant digits for the coordinates in the GeoJSON representation – the default value is 8.
`crs` | Set this to `True` if you want the coordinate reference system to be included in the returned GeoJSON.
`bbox` | Set this to `True` if you want the bounding box to be included in the returned GeoJSON.

#### `gml`

`GeoQuerySet.``gml`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `AsGML` function instead.

Availability: PostGIS, Oracle, SpatiaLite

Attaches a `gml` attribute to every model in the queryset that contains the Geographic Markup Language (GML) representation of the geometry.

Example:

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

Keyword Argument | Description
--- | ---
`precision` | This keyword is for PostGIS only. It may be used to specify the number of significant digits for the coordinates in the GML representation – the default value is 8.
`version` | This keyword is for PostGIS only. It may be used to specify the GML version used, and may only be values of 2 or 3. The default value is 2.

#### `kml`

`GeoQuerySet.``kml`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `AsKML` function instead.

Availability: PostGIS, SpatiaLite

Attaches a `kml` attribute to every model in the queryset that contains the Keyhole Markup Language (KML) representation of the geometry fields. It should be noted that the contents of the KML are transformed to WGS84 if necessary.

Example:

    >>> qs = Zipcode.objects.all().kml()
    >>> print(qs[0].kml)
    <Polygon><outerBoundaryIs><LinearRing><coordinates>-103.04135,36.217596,0 ... -103.04135,36.217596,0</coordinates></LinearRing></outerBoundaryIs></Polygon>

Keyword Argument | Description
--- | ---
`precision` | This keyword may be used to specify the number of significant digits for the coordinates in the KML representation – the default value is 8.

#### `svg`

`GeoQuerySet.``svg`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `AsSVG` function instead.

Availability: PostGIS, SpatiaLite

Attaches a `svg` attribute to every model in the queryset that contains the Scalable Vector Graphics (SVG) path data of the geometry fields.

Keyword Argument | Description
--- | ---
`relative` | If set to `True`, the path data will be implemented in terms of relative moves. Defaults to `False`, meaning that absolute moves are used instead.
`precision` | This keyword may be used to specify the number of significant digits for the coordinates in the SVG representation – the default value is 8.

### Miscellaneous

#### `mem_size`

`GeoQuerySet.``mem_size`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `MemSize` function instead.

Availability: PostGIS

Returns the memory size (number of bytes) that the geometry field takes in a `mem_size` attribute on each element of the `GeoQuerySet`.

#### `num_geom`

`GeoQuerySet.``num_geom`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `NumGeometries` function instead.

Availability: PostGIS, Oracle, SpatiaLite

Returns the number of geometries in a `num_geom` attribute on each element of the `GeoQuerySet` if the geometry field is a collection (e.g., a `GEOMETRYCOLLECTION` or `MULTI*` field); otherwise sets with `None`.

#### `num_points`

`GeoQuerySet.``num_points`(**kwargs)

Αποσύρθηκε στην έκδοση 1.9: Use the `NumPoints` function instead.

Availability: PostGIS, Oracle, SpatiaLite

Returns the number of points in the first linestring in the geometry field in a `num_points` attribute on each element of the `GeoQuerySet`; otherwise sets with `None`.

### Aggregate Functions

Django provides some GIS-specific aggregate functions. For details on how to use these aggregate functions, see the topic guide on aggregation.

Keyword Argument | Description
--- | ---
`tolerance` | This keyword is for Oracle only. It is for the tolerance value used by the `SDOAGGRTYPE` procedure; the Oracle documentation has more details.

Example:

    >>> from django.contrib.gis.db.models import Extent, Union
    >>> WorldBorder.objects.aggregate(Extent('mpoly'), Union('mpoly'))

#### `Collect`

class `Collect`(geo_field)

Availability: PostGIS, SpatiaLite

Returns a `GEOMETRYCOLLECTION` or a `MULTI` geometry object from the geometry column. This is analogous to a simplified version of the `Union` aggregate, except it can be several orders of magnitude faster than performing a union because it simply rolls up geometries into a collection or multi object, not caring about dissolving boundaries.

#### `Extent`

class `Extent`(geo_field)

Availability: PostGIS, Oracle, SpatiaLite

Returns the extent of all `geo_field` in the `QuerySet` as a four-tuple, comprising the lower left coordinate and the upper right coordinate.

Example:

    >>> qs = City.objects.filter(name__in=('Houston', 'Dallas')).aggregate(Extent('poly'))
    >>> print(qs['poly__extent'])
    (-96.8016128540039, 29.7633724212646, -95.3631439208984, 32.782058715820)

#### `Extent3D`

class `Extent3D`(geo_field)

Availability: PostGIS

Returns the 3D extent of all `geo_field` in the `QuerySet` as a six-tuple, comprising the lower left coordinate and upper right coordinate (each with x, y, and z coordinates).

Example:

    >>> qs = City.objects.filter(name__in=('Houston', 'Dallas')).aggregate(Extent3D('poly'))
    >>> print(qs['poly__extent3d'])
    (-96.8016128540039, 29.7633724212646, 0, -95.3631439208984, 32.782058715820, 0)

#### `MakeLine`

class `MakeLine`(geo_field)

Availability: PostGIS, SpatiaLite

Returns a `LineString` constructed from the point field geometries in the `QuerySet`. Currently, ordering the queryset has no effect.

SpatiaLite support was added.

Example:

    >>> qs = City.objects.filter(name__in=('Houston', 'Dallas')).aggregate(MakeLine('poly'))
    >>> print(qs['poly__makeline'])
    LINESTRING (-95.3631510000000020 29.7633739999999989, -96.8016109999999941 32.7820570000000018)

#### `Union`

class `Union`(geo_field)

Availability: PostGIS, Oracle, SpatiaLite

This method returns a `GEOSGeometry` object comprising the union of every geometry in the queryset. Please note that use of `Union` is processor intensive and may take a significant amount of time on large querysets.

Σημείωση

If the computation time for using this method is too expensive, consider using `Collect` instead.

Example:

    >>> u = Zipcode.objects.aggregate(Union(poly))  # This may take a long time.
    >>> u = Zipcode.objects.filter(poly__within=bbox).aggregate(Union(poly))  # A more sensible approach.

Footnotes

[1] | See OpenGIS Simple Feature Specification For SQL, at Ch. 2.1.13.2, p. 2-13 (The Dimensionally Extended Nine-Intersection Model).

[2] | See SDO_RELATE documentation, from Ch. 11 of the Oracle Spatial User’s Guide and Manual.

[3] | (1, 2) For an explanation of this routine, read Quirks of the “Contains” Spatial Predicate by Martin Davis (a PostGIS developer).

[4] | Refer to the PostGIS `ST_ContainsProperly` documentation for more details.