extract_items
This document has been machine translated.
Symbolically converts the transaction table based on the category definition.
The execution method uses JSON-RPC v2.0.
Example request
extract_items is a kind of analysis API, which can be executed by specifying api_method="extract_items" to the process method of the Provenance API.
The following is an example of starting a Provenance session, executing extract_items, and closing the session.
import xdata_prov.client import Api
api = Api()
api.begin_session()
api.process(api_method="extract_items", api_params={
"output_ddc": "ddc:jartic_xrain_items",
"input_ddc": "ddc:jartic_xrain_transaction",
"category_ddc": "ddc:jartic_xrain_category"
})
api.commit()
api.end_session()
Parameters
When calling the process method with api_method="extract_items", api_params will take a dict containing the following keys.
Parameters with a blank default value are required.
| key | description | default value |
|---|---|---|
| output_ddc | registered to ddc | |
| output_mode | output mode (overwrite or error) |
error |
| input_ddc | input data ddc | |
| category_ddc | category definition ddc |
input_data
transaction table
The input ddc specified by input_ddc is a "transaction table".
This table must have the following schema.
| column name | data type | description |
|---|---|---|
| id | integer | ID that uniquely identifies the transaction |
| start_datetime | timestamp with time zone | start date and time |
| end_datetime | timestamp with time zone | end_date |
| location | geometry | spatial range |
| meshcode | character varying | meshcode |
| * | arbitrary theme attribute |
Category definition table
The input ddc, specified by category_ddc, is the "category definition table".
This table must have the following schema.
| column name | data type | description |
|---|---|---|
| item | text | column name |
| min | double precision | minimum value (including the specified value) |
| max | double precision | maximum value (does not contain the specified value) |
| category | text | category string |
Output data
symbol-translated transaction table.
The "symbolic-translated transaction table" will be output to the destination ddc specified by output_ddc.
This table has the following schema.
| column name | data type | description |
|---|---|---|
| id | integer | ID that uniquely identifies the transaction |
| start_datetime | timestamp with time zone | start date and time |
| end_datetime | timestamp with time zone | end_date and time |
| location | geometry | spatial range |
| meshcode | character varying | meshcode |
| * | Transaction Table Theme Attributes | |
| items | text[] | a set of events that occurred in this space-time range |
return value
extract_items returns the ddc information of the destination ddc.
This is the behavior defined by the specification of the process method of the Provenance API.