# SqlGeography Class

The SqlGeography type represents data in a geodetic (round earth) coordinate system.

## Inheritance Hierarchy

System.Object

Microsoft.SqlServer.Types.SqlGeography

**Namespace:** Microsoft.SqlServer.Types

**Assembly:** Microsoft.SqlServer.Types (in Microsoft.SqlServer.Types.dll)

## Syntax

```
'Declaration
<SerializableAttribute> _
<CLSCompliantAttribute(True)> _
<SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered := False, _
MaxByteSize := , IsFixedLength := False)> _
Public NotInheritable Class SqlGeography _
Implements INullable, IBinarySerialize
'Usage
Dim instance As SqlGeography
```

```
[SerializableAttribute]
[CLSCompliantAttribute(true)]
[SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered = false,
MaxByteSize = , IsFixedLength = false)]
public sealed class SqlGeography : INullable,
IBinarySerialize
```

```
[SerializableAttribute]
[CLSCompliantAttribute(true)]
[SqlUserDefinedTypeAttribute(Format::UserDefined, IsByteOrdered = false,
MaxByteSize = , IsFixedLength = false)]
public ref class SqlGeography sealed : INullable,
IBinarySerialize
```

```
[<SealedAttribute>]
[<SerializableAttribute>]
[<CLSCompliantAttribute(true)>]
[<SqlUserDefinedTypeAttribute(Format.UserDefined, IsByteOrdered = false,
MaxByteSize = , IsFixedLength = false)>]
type SqlGeography =
class
interface INullable
interface IBinarySerialize
end
```

```
public final class SqlGeography implements INullable, IBinarySerialize
```

The SqlGeography type exposes the following members.

## Constructors

Name | Description | |
---|---|---|

SqlGeography | Initializes a new instance of the SqlGeography class. |

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## Properties

Name | Description | |
---|---|---|

IsNull | Determines whether the SqlGeography instance is null. | |

Lat | Returns the latitude property of the geography instance. | |

Long | Returns the longitude property of the geography instance. | |

M | Returns the M (measure) value of the geography instance. | |

Null | Returns a read-only property providing a null instance of the SqlGeography type. | |

STSrid | Gets or sets id is an integer representing the Spatial Reference Identifier (SRID) of the instance. | |

Z | Gets the Z (elevation) value of the instance. The semantics of the elevation value are user-defined. |

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## Methods

Name | Description | |
---|---|---|

AsGml | Returns the Geography Markup Language (GML) representation of a SqlGeography instance. | |

AsTextZM | Returns the Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation of a SqlGeography instance augmented with any Z (elevation) and M (measure) values carried by the instance. | |

BufferWithTolerance | Returns a geometric object representing the union of all point values whose distance from a SqlGeography instance is less than or equal to a specified value, allowing for a specified tolerance. | |

EnvelopeAngle | Returns the maximum angle between the point returned by the EnvelopeCenter method and a point in the geography instance in degrees. | |

EnvelopeCenter | Returns a point that can be used as the center of a bounding circle for the geography instance. | |

Equals | (Inherited from Object.) | |

Filter | Offers a fast, index-only intersection method to determine if a geography instance intersects another SqlGeography instance, assuming an index is available. | |

Finalize | (Inherited from Object.) | |

GeomFromGml | Constructs a SqlGeography instance given a representation in the SQL Server subset of the Geography Markup Language (GML). | |

GetHashCode | (Inherited from Object.) | |

GetType | (Inherited from Object.) | |

InstanceOf | Tests if the SqlGeography instance is the same as the specified type. | |

MemberwiseClone | (Inherited from Object.) | |

NumRings | Returns the total number of rings in a Polygon instance. | |

Parse | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation. | |

Point | Constructs a SqlGeography instance representing a Point instance from its x and y values and a spatial reference ID (SRID). | |

Populate | Applies a geography type call sequence to IGeographySink object. The call sequence is a set of figures, lines, and points for geography types. | |

Read | Reads a binary representation of a geography type into a SqlGeometry object. | |

Reduce | Returns an approximation of the given geography instance produced by running the Douglas-Peucker algorithm on the instance with the given tolerance. | |

RingN | Returns the specified ring of the SqlGeography instance: 1 ≤ n ≤ NumRings(). | |

STArea | Returns the total surface area of a SqlGeography instance. | |

STAsBinary | Returns the Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation of a SqlGeography instance. | |

STAsText | Returns the Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation of a SqlGeography instance. | |

STBuffer | Returns a geography object that represents the union of all points whose distance from a SqlGeography instance is less than or equal to a specified value. | |

STDifference | Returns an object representing the points from one SqlGeography instance that do not lie within another SqlGeography instance. | |

STDimension | Returns the maximum dimension of a SqlGeography instance | |

STDisjoint | Determines whether the calling SqlGeography instance is spatially disjoint from the specified SqlGeography instance. | |

STDistance | Returns the shortest distance between a point in a SqlGeography instance and a point in another SqlGeography instance. | |

STEndPoint | Returns the end point of a SqlGeography instance. | |

STEquals | Determines whether the specified SqlGeography instance has the same point set as the calling SqlGeography instance. | |

STGeomCollFromText | Returns a geography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation, augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STGeomCollFromWKB | Returns a GeometryCollection instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STGeometryN | Returns a specified geography element in a GeometryCollection or one of its subtypes. | |

STGeometryType | Returns the Open Geospatial Consortium (OGC) type name represented by a geography instance. | |

STGeomFromText | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STGeomFromWKB | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STIntersection | Returns an object representing the points where a SqlGeography instance intersects another SqlGeography instance. | |

STIntersects | Determines whether the current SqlGeography instance intersects with the specified SqlGeography. | |

STIsClosed | Determines whether the calling SqlGeography instance is closed. | |

STIsEmpty | Determines whether the SqlGeography instance is empty. | |

STLength | Returns the total length of the elements in a SqlGeography instance or the SqlGeography instances within a GeometryCollection. | |

STLineFromText | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation, augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STLineFromWKB | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation, augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STMLineFromText | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation, augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STMLineFromWKB | Returns a SqlGeography MultiLineString instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STMPointFromText | ||

STMPointFromWKB | Returns a SqlGeography MultiPoint instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STMPolyFromText | ||

STMPolyFromWKB | Returns a SqlGeography MultiPolygon instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STNumGeometries | Returns the number of geometries that make up a SqlGeography instance. | |

STNumPoints | Returns the total number of points in each of the figures in a SqlGeography instance | |

STPointFromText | ||

STPointFromWKB | Returns a SqlGeography Point instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STPointN | Returns the specified point in a SqlGeography instance. | |

STPolyFromText | Returns a SqlGeography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation augmented with any Z (elevation) and M (measure) values carried by the instance. | |

STPolyFromWKB | Returns a SqlGeography Polygon instance from an Open Geospatial Consortium (OGC) Well-Known Binary (WKB) representation. | |

STStartPoint | Returns the start point of a SqlGeography instance. | |

STSymDifference | Returns an object representing all points that are either in one SqlGeography instance or another SqlGeography instance, but not those points that lie in both instances. | |

STUnion | Returns an object representing the union of a SqlGeography instance with another SqlGeography instance. | |

ToString | Returns the Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation of a SqlGeography instance augmented with any Z (elevation) and M (measure) values carried by the instance. (Overrides Object.ToString().) | |

Write | Writes a SqlGeography object to a binary stream. |

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## Remarks

SQL Server 2008 supports a set of methods for the geography spatial data type. These methods include methods on geography that are defined by the Open Geospatial Consortium (OGC) standard and a set of Microsoft extensions to that standard.

## Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.