GeoCSV: Unterschied zwischen den Versionen
Aus Geoinformation HSR
Stefan (Diskussion | Beiträge) K |
Stefan (Diskussion | Beiträge) K |
||
Zeile 22: | Zeile 22: | ||
* [WKT] ("Well Known Text") is originally defined by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access specification (also ISO SQL/MM). | * [WKT] ("Well Known Text") is originally defined by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access specification (also ISO SQL/MM). | ||
* Its a String containing a constructor, like for example: "POINT (47.2274,8.8249)". | * Its a String containing a constructor, like for example: "POINT (47.2274,8.8249)". | ||
− | * This option supports | + | * This option supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon. |
* See e.g. http://en.wikipedia.org/wiki/Well-known_text | * See e.g. http://en.wikipedia.org/wiki/Well-known_text | ||
+ | Common restrictions: | ||
+ | * All values within one table are in the same coordinate reference system ([[CRS]]). | ||
+ | * There is only one geometry column allowed. | ||
=== CSVT file format specification === | === CSVT file format specification === |
Version vom 30. April 2015, 14:14 Uhr
Specification of a 'modern' CSV with a geometry extension of either two easting/northing colums or one WKT column!
CSV file format specification
- Encoding is UTF-8 by default.
- First row contains attribute names separated by a => delimiter.
- Following rows are contains values separated by a => delimiter.
- Delimiter is semicolon (;) by default.
- Strings are enclosed by parantheses, to allow delimiters inside (e.g. "string").
- Data types (if supported from source or target system): See CSVT file format specification.
- Coordinate system is WGS84 (EPSG:4326) by default.
GeoCSV file format specification
GeoCSV is based on CSV. The extension comes with two variants: Options easting/northing and Options WKT
Options "easting/northing" (similar to x/y in mathematics):
- Geometry Point type as two neighboring columns: one containing the easting coordinate, and one containing northing coordinate separated by the common delimiter.
- Example for the two easting/northing columnts "47.2274;8.8249".
- This option supports only Points.
Options WKT:
- [WKT] ("Well Known Text") is originally defined by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access specification (also ISO SQL/MM).
- Its a String containing a constructor, like for example: "POINT (47.2274,8.8249)".
- This option supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon.
- See e.g. http://en.wikipedia.org/wiki/Well-known_text
Common restrictions:
- All values within one table are in the same coordinate reference system (CRS).
- There is only one geometry column allowed.
CSVT file format specification
Field/column types (if supported from source or target system):
- Integer
- Real
- String
- Date ("YYYY-MM-DD"), Time ("HH:MM:SS+nn") and DateTime (YYYY-MM-DD HH:MM:SS+nn)
See also http://www.gdal.org/drv_csv.html section with .csvt extension.