docs/api/sql/box2d/Box2D-Constructors/ST_GeomFromBox2D.md

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# ST_GeomFromBox2D

Introduction: Convert a `Box2D` to a closed rectangular polygon `Geometry`. Equivalent to PostGIS `box2d::geometry`. Degenerate boxes return the appropriate lower-dimensional geometry:

| Box2D shape                                                | Returned geometry |
| :---                                                       | :--- |
| Both axes have non-zero extent                             | `POLYGON` (closed rectangle) |
| One axis collapsed (e.g. `xmin == xmax`)                   | `LINESTRING` along the non-collapsed axis |
| Both axes collapsed (`xmin == xmax && ymin == ymax`)       | `POINT` |

Format: `ST_GeomFromBox2D(box: Box2D)`

Return type: `Geometry`

Since: `v1.9.1`

SQL Example

```sql
SELECT ST_AsText(ST_GeomFromBox2D(ST_MakeBox2D(ST_Point(0.0, 0.0), ST_Point(2.0, 4.0))))
```

Output:

```
POLYGON ((0 0, 0 4, 2 4, 2 0, 0 0))
```

`ST_GeomFromBox2D` is also produced by the SQL cast `CAST(box AS geometry)` — see [Type conversion](../Box2D-Functions.md#type-conversion).

Returns `NULL` on `NULL` input.