GeoPackage FormatΒΆ
The GeoPackage is an open and standard format, portable and platform independent.
The format describes rules for storing geospatial data (vector and raster) within a SQLite database.
The format requires a SQLite database file with .gpkg extension.
Tables Overview
gpkg_spatial_ref_sys
This table contains records to define all spatial reference systems used by the table contents in the GeoPacakge itself.
- Where:
- srs_name: name of the SRS
- srs_id: unique identifier for each SRS within the database
- organization: name of the defininig organization
- organization_coordsys_id: numeric ID of the SRS assigned by the organization
- definition: WKT representation of the SRS
- description: description of the SRS
gpkg_geometry_columns
This table identifies the geometry columns and geometry types in tables that contain user data representing features.
- Where:
- table_name: name of the geometry table
- column_name: name of the geometry column
- geometry_type_name: name of the geometry type (eg. POINT, POLYGON)
- srs_id: SRS ID of the data in the geometry column
- z: enumerator for Z values (0: prohibited, 1: mandatory, 2: optional)
- m: enumerator for M values (0: prohibited, 1: mandatory, 2: optional)
gpkg_contents
- Where:
- table_name: name of the actual content table
- data_type: type of the data stored in the table (eg. tiles, features, attributes) table
- identifier: a short name identifier for the table_name content
- description: a description for the table_name content
- last_change: timestamp of the last change of the content
- min_x: minimum Easting or Longitude for all content in the table
- min_y: minimum Northing or Latitude for all content in the table
- max_x: maximum Easting or Longitude for all content in the table
- max_y: maximum Northing or Latitude for all content in the table
- srs_id: Spatial reference System ID (referencing gpkg_sptial_ref_sys.srs_id)
gpkg_tile_matrix_set This table contains coordinates that define a bounding box as the exact stated spatial extent for all tiles in a tile (matrix set) table. If the geographic extent of the image data contained in tiles at a particular zoom level is within but not equal to this bounding box, then the non-image area of matrix edge tiles must be padded with no-data values, preferably transparent ones.
- Where:
- table_name: name of the Tile Pyramid table
- srs_id: Spatial reference System ID (referencing gpkg_sptial_ref_sys.srs_id)
- min_x: minimum Easting or Longitude for the tile matrix set
- min_y: minimum Northing or Latitude for the tile matrix set
- max_x: maximum Easting or Longitude for the tile matrix set
- max_y: maximum Northing or Latitude for the tile matrix set
gpkg_tile_matrix
- Where:
- table_name: name of the Tile Pyramid table
- zoom_level: zoom level
- matrix_width: number of columns for the specific zoom_level
- matrix_height: number of rows for the specific zoom_level
- tile_width: tile width in pixels for the specific zoom level
- tile_height: tile height in pixels for the specific zoom level
- pixel_x_size: width of the pixel in the table SRID unit (default meters)
- pixel_y_size: height of the pixel in the table SRID unit (default meters)