Non-spatial attribute data are sets (or tuples or rows) of observations that may not have an explicit geometry property. In GeoPackage, this data is stored in user-defined attribute tables. These tables may contain properties such as an ID or geo-locatable address that allow them to be relationally linkable to rows in other attribute, feature or tile tables.
Examples of attribute data include:
-
meteorological readings from a weather station
-
flow readings from a stream gauge
-
traffic volumes from embedded highway sensors
-
lists of customers
-
delivery stops
-
work orders
Non-spatial attribute data is stored in user-defined Attribute tables. Attribute sets are rows in an Attribute table. The attributes are columns in a Attribute table. (A GeoPackage is not required to contain any Attribute data tables. Attribute data tables in a GeoPackage may be empty.)
A GeoPackage MAY contain tables or updatable views containing attribute sets. Every such Attribute table or view in a GeoPackage SHALL have a column with column type INTEGER and PRIMARY KEY AUTOINCREMENT column constraints per GeoPackage Attributes Example Table or View Definition and [example_attributes_table_sql].
The integer primary key of an Attribute table allows attribute sets to be linked to row level metadata records in the gpkg_metadata table by rowid [B5] values in the gpkg_metadata_reference table as described in clause [extension_metadata] below.
Column Name | Col Type | Column Description | Null | Key |
---|---|---|---|---|
|
INTEGER |
Autoincrement primary key |
no |
PK |
|
TEXT |
Text attribute of feature |
yes |
|
|
REAL |
Real attribute of feature |
yes |
|
|
BOOLEAN |
Boolean attribute of feature |
yes |
|
|
BLOB |
Photo of the area |
yes |