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| |
| # ST_Box2D |
| |
| Introduction: Return the planar bounding box of a Geometry as a typed `Box2D` value (four doubles: `xmin`, `ymin`, `xmax`, `ymax`). |
| |
| `ST_Box2D` is the typed counterpart to [ST_Envelope](../../Bounding-Box-Functions/ST_Envelope.md). `ST_Envelope` returns the envelope as a `Geometry` — typically a polygon, but JTS may return a `Point` or `LineString` for degenerate inputs. `ST_Box2D` always returns a `Box2D` value that serialises to a struct of four non-nullable doubles and round-trips through Parquet without WKB overhead. |
| |
| Format: `ST_Box2D(geom: Geometry)` |
| |
| Return type: `Box2D` |
| |
| Since: `v1.9.1` |
| |
| SQL Example |
| |
| ```sql |
| SELECT ST_AsText(ST_Box2D(ST_GeomFromWKT('LINESTRING (0 0, 10 20)'))) |
| ``` |
| |
| Output: |
| |
| ``` |
| BOX(0.0 0.0, 10.0 20.0) |
| ``` |
| |
| `ST_Box2D` is also produced by the SQL cast `CAST(geom AS box2d)` — see [Type conversion](../Box2D-Functions.md#type-conversion). |
| |
| Returns `NULL` for `NULL` or empty geometry input. |
