# Geometry union

> Supported in: Batch, Faster, Streaming

Combines the two geometries to create a single geometry.

**Expression categories:** Geospatial

## Declared arguments

* **Geometry a:** Geometry a.<br>*Expression\<Geometry>*
* **Geometry b:** Geometry b.<br>*Expression\<Geometry>*

**Output type:** *Geometry*

## Examples

### Example 1: Base case

**Argument values:**

* **Geometry a:** `geometry_a`
* **Geometry b:** `geometry_b`

| geometry\_a | geometry\_b | **Output** |
| ----- | ----- | ----- |
| {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[0.5,0.0],\[1.5,0.0],\[1.5,1.0],\[0.5,1.0],\[0.5,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[0.5,1.0],\[1.0,1.0],\[1.5,1.0],\[1.5,0.0],\[1.0,0.0],\[0.5,0.0],\[0.0,0.0]]]} |
| {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[5.0,5.0],\[5.0,6.0],\[6.0,6.0],\[6.0,5.0],\[5.0,5.0]]]} | {"type":"MultiPolygon","coordinates":\[\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]],\[\[\[5.0,5.0],\[5.0,6.0],\[6.0,6.0],\[6.0,5.0],\[5.0,5.0]]]]} |
| {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[1.0,0.0],\[1.0,1.0],\[2.0,1.0],\[2.0,0.0],\[1.0,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[2.0,1.0],\[2.0,0.0],\[1.0,0.0],\[0.0,0.0]]]} |
| {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]]} | {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]],\[\[0.25,0.25],\[0.5,0.25],\[0.5,0.5],\[0.25,0.5],\[0.25,0.25]]]} | {"type":"Polygon","coordinates":\[\[\[0.0,0.0],\[0.0,1.0],\[1.0,1.0],\[1.0,0.0],\[0.0,0.0]]]} |
| {"type":"LineString","coordinates":\[\[0.0,0.0],\[1.0,0.0]]} | {"type":"Polygon","coordinates":\[\[\[1.0,0.0],\[1.0,1.0],\[2.0,1.0],\[2.0,0.0],\[1.0,0.0]]]} | {"type":"GeometryCollection","geometries":\[{"type":"LineString","coordinates":\[\[0.0,0.0],\[1.0,0.0]]},{"type":"Polygon","coordinates":\[\[\[1.0,0.0],\[1.0,1.0],\[2.0,1.0],\[2.0,0.0],\[1.0,0.0]]]}]} |

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