---
title: "GeometryCollection | Microsoft Docs"
ms.date: "03/01/2017"
ms.prod: sql
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  - "GeomCollection geometry subtype [SQL Server]"
  - "geometry subtypes [SQL Server]"
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author: MladjoA
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---
# GeometryCollection
[!INCLUDE[appliesto-ss-asdb-xxxx-xxx-md](../../includes/appliesto-ss-asdb-xxxx-xxx-md.md)]
  A **GeometryCollection** is a collection of zero or more **geometry** or **geography** instances. A **GeometryCollection** can be empty.  
  
## GeometryCollection Instances  
  
### Accepted Instances  
 For a **GeometryCollection** instance to be accepted, it must either be an empty **GeometryCollection** instance or all the instances comprising the **GeometryCollection** instance must be accepted instances. The following example shows accepted instances.  
  
```sql  
DECLARE @g1 geometry = 'GEOMETRYCOLLECTION EMPTY';  
DECLARE @g2 geometry = 'GEOMETRYCOLLECTION(LINESTRING EMPTY,POLYGON((-1 -1, -1 -5, -5 -5, -5 -1, -1 -1)))';  
DECLARE @g3 geometry = 'GEOMETRYCOLLECTION(LINESTRING(1 1, 3 5),POLYGON((-1 -1, -1 -5, -5 -5, -5 -1, -1 -1)))';  
```  
  
 The following example throws a `System.FormatException` because the **LinesString** instance in the **GeometryCollection** instance is not accepted.  
  
```sql  
DECLARE @g geometry = 'GEOMETRYCOLLECTION(LINESTRING(1 1), POLYGON((-1 -1, -1 -5, -5 -5, -5 -1, -1 -1)))';  
```  
  
### Valid Instances  
 A **GeometryCollection** instance is valid when all instances that comprise the **GeometryCollection** instance are valid. The following shows three valid **GeometryCollection** instances and one instance that is not valid.  
  
```sql  
DECLARE @g1 geometry = 'GEOMETRYCOLLECTION EMPTY';  
DECLARE @g2 geometry = 'GEOMETRYCOLLECTION(LINESTRING EMPTY,POLYGON((-1 -1, -1 -5, -5 -5, -5 -1, -1 -1)))';  
DECLARE @g3 geometry = 'GEOMETRYCOLLECTION(LINESTRING(1 1, 3 5),POLYGON((-1 -1, -1 -5, -5 -5, -5 -1, -1 -1)))';  
DECLARE @g4 geometry = 'GEOMETRYCOLLECTION(LINESTRING(1 1, 3 5),POLYGON((-1 -1, 1 -5, -5 5, -5 -1, -1 -1)))';  
SELECT @g1.STIsValid(), @g2.STIsValid(), @g3.STIsValid(), @g4.STIsValid();  
```  
  
 `@g4` is not valid because the **Polygon** instance in the **GeometryCollection** instance is not valid.  
  
 For more information on accepted and valid instances, see [Point](../../relational-databases/spatial/point.md), [MultiPoint](../../relational-databases/spatial/multipoint.md), [LineString](../../relational-databases/spatial/linestring.md), [MultiLineString](../../relational-databases/spatial/multilinestring.md), [Polygon](../../relational-databases/spatial/polygon.md), and [MultiPolygon](../../relational-databases/spatial/multipolygon.md).  
  
## Examples  
 The following example instantiates a `geometry``GeometryCollection` with Z values in SRID 1 containing a `Point` instance and a `Polygon` instance.  
  
```sql  
DECLARE @g geometry;  
SET @g = geometry::STGeomCollFromText('GEOMETRYCOLLECTION(POINT(3 3 1), POLYGON((0 0 2, 1 10 3, 1 0 4, 0 0 2)))', 1);  
```  
  
## See Also  
 [Spatial Data (SQL Server)](../../relational-databases/spatial/spatial-data-sql-server.md)