Feature Representation
In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this section.
| Attribute Name | Contents |
|---|---|
| couchdb_id |
This format attribute is the alphanumeric ID for the document which represents the feature on the CouchDB server. This ID is unique among all features of a given feature type. Input features that do not have a couchdb_id attribute will be assigned a unique ID by CouchDB. You must ensure that any user-specified IDs are globally-unique on the CouchDB server. Note: The couchdb_id attribute is not modifiable once the document has been created. |
| couchdb_rev (read only) |
This format attribute is the revision ID for the last time the server’s document was modified expressed as a hexadecimal string. The couchdb_rev attribute of a CouchDB document is regenerated each time the document is edited (including modifications to the couchdb_rev attribute). Because of this, you cannot set the couchdb_rev attribute. |
| couchdb_raw_json |
This format attribute represents the document as serialized JSON. If Read Original JSON Document is enabled on the reader, output features will contain the serialized JSON in this attribute. |
CouchDB attributes cannot have names that contain non-ASCII characters; however, the attribute values support full UTF-8.
The CouchDB attribute type mapping is as follows.
| CouchDB Attribute Type | FME Attribute Type |
|---|---|
|
string(width) |
fme_varchar(width) |
|
string(width) |
fme_char(width) |
|
string(255) |
fme_buffer |
|
string(1) |
fme_char |
|
real(width, decimal) |
fme_decimal(width, decimal) |
|
string(24) |
fme_datetime |
|
string(8) |
fme_date |
|
string(10) |
fme_time |
|
integer |
fme_int32 |
|
real(10,0) |
fme_uint32 |
|
real(20,0) |
fme_int64 |
|
real(20,0) |
fme_uint64 |
|
integer |
fme_int16 |
|
integer |
fme_uint16 |
|
integer |
fme_uint8 |
|
real(15,7) |
fme_real32 |
|
real(31,15) |
fme_real64 |
|
integer |
fme_boolean |
Geometry
The geometry of CouchDB features may be identified by the wkb_type attribute. The valid values for this attribute are:
| couchdb_type | Description |
|---|---|
| wkb_none | FME Feature with no geometry |
| wkb_point | 2D Point feature |
| wkb_point_xyz | 2.5D Point feature |
| wkb_line | 2D Linear feature |
| wkb_line_xyz | 2.5D Linear feature |
| wkb_polygon | 2D Simple polygon or donut feature |
| wkb_polygon | 2.5D Simple polygon or donut feature |
| wkb_geometry_collection | 2D Feature with multiple geometries |
| wkb_geometry_collection_xyz | 2.5D Feature with multiple heterogeneous geometries |
| wkb_multi_point | 2D Feature with multiple heterogeneous point geometries |
| wkb_multi_point_xyz | 2.5D Feature with multiple heterogeneous point geometries |
| wkb_multi_line | 2D Feature with multiple line geometries |
| wkb_multi_line_xyz | 2.5D Feature with multiple line geometries |
| wkb_multi_polygon | 2D Feature with multiple polygon geometries |
| wkb_multi_polygon_xyz | 2.5D Feature with multiple polygon geometries |
| wkb_geometry | All geometries allowed |
| wkb_unknown | All geometries allowed |