In addition to the generic FME feature attributes that FME Workbench adds to all features, this format adds the format-specific attributes described in this section.
The OGDI feature attributes consist of the columns that were in the Microsoft Windows Azure Table. All OGDI features contain an ogdi_type attribute, which is set to ogdi_<geometry type> for any supported geometry.
The OGDI format uses KML snippets to keep the geometry in the Windows Azure Table.
The following table summarizes the attribute types supported:
|
Parameter |
Contents |
| text | Text attributes store variable length strings. This type is also used to store date values. |
| integer | Integer attributes store integer numbers in contrast to floating point numbers. |
| boolean | Boolean attributes store true or false values. |
| number | Number attributes store floating point numbers. |
The OGDI module makes use of the following special attribute names:
|
Attribute Name |
Contents |
| ogdi_type |
The type of geometric entity stored within the feature. The valid values for the object model are listed below: ogdi_none ogdi_point ogdi_line ogdi_area ogdi_aggregate |
| ogdi_last_update | The UTC date and time value formatted as a string representing the time this table was last updated. For example: 2010-10-12 18:23:47.574000 |
| ogdi_partitionkey | The unique value for partition that this row will be a part of. Partitioning helps with load balancing on the server when retrieving data. If no value is provided a single GUID will be used for all ll feature written I a given translation for each table. Any text value is permissible. |
| ogdi_rowkey |
Specifies or retrieves a unique identifier per row. If set, this should be unique per input feature. If a value is not provided, a unique GUID will be generated for each row inserted into a given table. |
| ogdi_kml_name | Specifies a name for the geometry stored at each row in the table. This name is written directly into the KML snippet. If a value is not provided, a value of 'None' will be written for the KML geometry name. |
| ogdi_kml_description | Specifies a description for the geometry stored at each row in the table. This description is written directly into the KML snippet. If a value is not provided, a value of 'None' will be written for the KML geometry name. |
No Coordinates
ogdi_type: ogdi_none
Features with no coordinates are tagged with this value when reading or writing to or from OGDI. Note also that this is a valid KML snippet but is not particularly significant.
Points
ogdi_type: ogdi_point
Features tagged with this value consist of a single point. Both singular points and aggregates of points are supported. Point aggregates will become aggregates while singular points will become points in OGDI.
Line
ogdi_type: ogdi_lines
Linear features are tagged with this value when reading or writing to or from OGDI. A line consists of one or more ordered two-point line segments. Line aggregates will become aggregates while singular lines will become lines in OGDI.
Area
ogdi_type: ogdi_area
Area or polygon features are tagged with this value when reading or writing to or from OGDI. Both single-part and aggregate area features are supported. A single area feature may be either a polygon or a donut polygon. Area aggregates will become aggregates while singular areas will become polygons in OGDI. Note that NO checking is done to ensure that the area features adhere to the geometry rules of OGDI as they are loaded.
GeometryCollections
ogdi_type: ogdi_aggregate
Aggregates containing either homogeneous or heterogeneous collections of point, line and polygon features are processed through FME as single features when reading to or writing from OGDI.