GeoCSV

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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.

Option "easting/northing" (longitude/latitude, similar to x/y in mathematics):

  • Geometry Point type as two neighboring columns of type Float: one containing the easting coordinate, and one containing northing coordinate separated by the common delimiter.
  • Example for the two easting/northing columnts "8.8249;47.2274".
  • This option supports only Points.

Option WKT:

  • It' one single column of type String containing a constructor, like for example: "POINT (8.8249 47.2274)".
  • This option supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon.
  • 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). See e.g. http://en.wikipedia.org/wiki/Well-known_text

Common restrictions:

  • There is only one geometry column allowed per sheet.
  • All geometry values within one table are in the same coordinate reference system (CRS).

CSVT file format specification

Field/column types, case insensitive (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)
  • (lon/lat)
  • (WKT)

Notes:

  • The geometry types are a kind of subtype: easting and northing values are stored as float, option WKT is stored in one column of type String.
  • See also http://www.gdal.org/drv_csv.html section with .csvt extension.