gpkgcontents

gpkg_contents is the core metadata table of the GeoPackage standard. It stores metadata for every content item contained in a geopackage file, such as feature data tables and tile matrices. Each row represents a single dataset and provides a concise description of what is stored and how to access it, enabling software to discover and enumerate the contents without inspecting every table.

Typical fields in gpkg_contents include table_name, data_type, identifier, description, last_change, min_x, max_x, min_y, max_y, and srs_id. The data_type value typically indicates whether the content represents features (vector data) or tiles (raster tile data). The table_name identifies the actual SQLite table that holds the data; identifier and description offer human-readable metadata; last_change records the last update time; and the extent fields (min_x, max_x, min_y, max_y) describe the geographic bounds of the content. The srs_id field references the spatial reference system defined in gpkg_spatial_ref_sys.

gpkg_contents also serves as a linkage point to other GeoPackage components. The srs_id value links to the corresponding spatial reference system, establishing the coordinate reference framework. For tile data, the existence of a gpkg_contents row is complemented by related tables such as gpkg_tile_matrix_set and gpkg_tile_matrix that describe tile matrix sets and levels of detail.

In use, gpkg_contents allows GIS tools and applications to enumerate available layers, filter by data_type or srs_id, and present metadata to users. It is a required component of the GeoPackage specification and supports interoperability and automated processing across tools and platforms.