Queries take data form different areas and are more user friendly than using endpoints. Output is usable without further manipulation.
tocSearch queries can be created manually or by building a query using the query generator within the EcoPlots portal search page.
Search queries are independent of the tools that are used for sending the query request. For example, the same query body can be used with a request written in cURL, python, postman, R, or another programming language.
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Remember that all data endpoints allow filtering!
The query parameter in the request body allows the data requested from any endpoint to be filtered according to the parameters specified. For example:
From the * endpoint, it is possible to retrieve only sites which contain a feature of interest (FOI) = , such as “plant occurrence”From the * endpoint, it is possible to retrieve
retrieve only observations which contain a parameter = (ie. “basal area”)
Understanding EcoPlots data queries
One of the strengths of EcoPlots is how its powerful the query system is. Data are stored as atomic elements (observations) allowing to filter by 0 to many facets.
Before the user starts to define queries, it is important to understand how the underlying system has been built. Values for every search category store a URI (Uniform Resource Identifier), instead of any human-readable value. In Within EcoPlots case, this URI is actually a resolvable URL identifying that identifies a unique concept or instance of a class.
"http://linked.data.gov.au/dataset/ausplots"
is the identifier of ausplots “ausplots” in TERN Surveillance Monitoring (a single instance of the Dataset class)
"http://linked.data.gov.au/def/tern-cv/b311c0d3-4a1a-4932-a39c-f5cdc1afa611"
is the identifier of “plant occurrence” (a * within the Concept class that belongs to of the Concept Scheme “Feature types”).
This * design The RDF data model (RDF - Semantic Web Standards (w3.org)) used in Ecoplots offers multiple benefits. Because a URI is a unique and immutable identifier for a specific concept, we can easily modify the vocabulary by changing the label, the description or any other property of the concept without having to update the data.
The only drawback to using URIs is that they are usually not human readable. However, all our URIs are resolvable using the HTTP protocol, meaning that you can paste the URI into your browser and retrieve all the details of the element.
What can be queried?
There are several different ways you can discover our vocabularies (the possible values in queries):
Inspecting the TERN vocabularies, then use the vocabulary URI of interest
Using the
/discover/{field}
endpoint. This endpoint returns a set of “key: value” (consisting of a label and uriURI) entries with all the possible values for every facet.
The filter query must be sent in the request body (content type JSON) along with any pagination parameters.
Query example:
General examples
Examples of valid queries
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Each of the below examples are syntactically valid ways to write a query requests for the EcoPlots API. All queries must contain a |
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{ "query": { "dataset": [ "http://linked.data.gov.au/dataset/ausplots" ], } } |
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{ "featurepage_typenumber": [1, "page_size": 50, "query"http://linked.data.gov.au/def/tern-cv/b311c0d3-4a1a-4932-a39c-f5cdc1afa611" { ], "observed_propertydataset": [ "http://linked.data.gov.au/def/tern-cv/0bbd7fcd-0782-4efc-96e6-1f0f7669c655dataset/ausplots" ] } } |
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Valid request bodies |
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{ "page_numberquery": 1,{ # optional "pagefeature_sizetype": 50,[ # optional "query": { # mandatory, but query can be empty http://linked.data.gov.au/def/tern-cv/b311c0d3-4a1a-4932-a39c-f5cdc1afa611" ] } } |
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{ "query": { "datasetobserved_property": [ "http://linked.data.gov.au/dataset/ausplotsdef/tern-cv/0bbd7fcd-0782-4efc-96e6-1f0f7669c655" ] } } |
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{ "page_number": 1, "page_size": 50, "query": {} } |
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{ "query": {} } |
Remember that comments within JSON invalidates the syntax. For first invalid example below, there must be a page number is there is a page size.
Common query syntax errors
If a query includes pagination, both the page_number
and the page_size
parameters must be included.
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Example of an invalid request. This request is invalid due to only including the |
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{ "page_number": 1, "query": {} } |
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Example of an invalid request. This request is invalid as the request body is empty. At a minimum, requests must contain a |
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{} |
Warning |
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Example of an invalid request. This request is invalid as the request body is empty. At a minimum, requests must contain a |
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{
"page_number": 1,
"page_size": 50
} |
Formatting the facets of a query object
Probably need a link to the index of possible query bodies.
Notice that all values (even if it is 1 single value) must be enclosed between square brackets.
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Valid query bodies |
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"dataset": [
" In these two examples, each value (in the first example |
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"dataset": [
" and in the second example both and |
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Invalid query bodies |
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"dataset": "http://linked.data.gov.au/dataset/ausplots" |
Adding an empty list is a valid request but the response will be always empty.
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"dataset": [] |
Region
Filter data whose site is located within a specific region.
Example 1 - Data collected in the Bioregion Cape York Peninsula
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"region": [
"http://linked.data.gov.au/dataset/bioregion/CYP"
] |
Example 2 - Data collected in the Queensland state
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"region" ) is enclosed within double quotations. In the second example, the values are separated by a comma and both values are enclosed within square brackets |
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"dataset": [ "http://linked.data.gov.au/dataset/asgs2016/stateorterritory/3" ] |
Example 3 - Data collected either in Tasmania or in Cape York Peninsula
ausplots"
] |
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"regiondataset": [ "http://linked.data.gov.au/dataset/asgs2016/stateorterritory/6ausplots", "http://linked.data.gov.au/dataset/bioregion/CYP" corveg" ] |
Dataset
Filter data by dataset.
Example - Data from “Tern Surveillance Monitoring” or “Williams Wet Tropics Vertebrates”
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"dataset": [
"http://linked.data.gov.au/dataset/ausplots",
"http://linked.data.gov.au/dataset/wet-tropics-vertebrate"
] |
Site
Retrieve data from 1 or more ecological monitoring sites.
Example - Retrieve all the data from Tern Surveillance Monitoring site nsabbs0001
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"site_id": [
"http://linked.data.gov.au/dataset/ausplots/site-nsabbs0001"
] |
Site Visit
Retrieve data from 1 or more ecological monitoring sites.
Example - Retrieve all the data from Tern Surveillance Monitoring sitevisit 58580
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Invalid query bodies The first example is invalid as there are no enclosing square brackets The second example is not technically invalid, however it will yield no results as the |
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"dataset": "http://linked.data.gov.au/dataset/ausplots |
" |
EcoPlots observations are categorised in Feature of Interest (FOI). Please see the FOI vocabularies for more detail.
Example - Retrieve all the data from Landform feature of interest
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" |
dataset": [ |
Parameter (observable property)
Each observation in EcoPlots is measuring an observable property (or parameter). Please see the Parameter vocabularies for more detail.
Example - Get all the data from Crown cover parameter.
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"observed_property": [
"http://linked.data.gov.au/def/tern-cv/83ac0278-51cd-4d1a-8e05-7c1fc68cf020"
] |
Temporal extent (date)
In addition to all the vocabularised facets, you can filter data based on a temporal resolution.
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"date_from": "2006-01-01",
"date_to": "2021-07-30" |
Spatial extent
Need to explain how this works and how to do this.
Statial queries in EcoPlots allows three different formats: GeoJSON, Well-Known Text (WKT) and Bounding Box. The spatial query will do an “intersect” between the given geometry and the geometry of the data.
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# WKT examples:
"spatial": "POINT (-77.03653 38.897676)"
"spatial": "LINESTRING (-77.03653 38.897676, -77.009051 38.889939)"
"spatial": "POLYGON ((100.0 0.0, 101.0 0.0, 101.0 1.0, 100.0 1.0, 100.0 0.0))"
"spatial": "MULTIPOINT (102.0 2.0, 103.0 2.0)"
"spatial": "MULTILINESTRING ((102.0 2.0, 103.0 2.0, 103.0 3.0, 102.0 3.0), (100.0 0.0, 101.0 0.0, 101.0 1.0, 100.0 1.0), (100.2 0.2, 100.8 0.2, 100.8 0.8, 100.2 0.8))"
"spatial": "MULTIPOLYGON (((102.0 2.0, 103.0 2.0, 103.0 3.0, 102.0 3.0, 102.0 2.0)), ((100.0 0.0, 101.0 0.0, 101.0 1.0, 100.0 1.0, 100.0 0.0), (100.2 0.2, 100.8 0.2, 100.8 0.8, 100.2 0.8, 100.2 0.2)))" |
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# GEOJSON examples:
"spatial": {
"type" : "Point",
"coordinates" : [-77.03653, 38.897676]
}
"spatial": {
"type" : "LineString",
"coordinates" : [[-77.03653, 38.897676], [-77.009051, 38.889939]]
}
"spatial": {
"type" : "Polygon",
"coordinates" : [
[ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ]
]
}
"spatial": {
"type" : "MultiPolygon",
"coordinates" : [
[ [[102.0, 2.0], [103.0, 2.0], [103.0, 3.0], [102.0, 3.0], [102.0, 2.0]] ],
[ [[100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0]],
[[100.2, 0.2], [100.8, 0.2], [100.8, 0.8], [100.2, 0.8], [100.2, 0.2]] ]
]
}
"spatial": {
"type": "MultiPoint",
"coordinates": [
[
139.213700000,
-34.358210000
],
[
150,
-35
]
]
} |
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# Bounding Box (BBOX) example
"spatial": [139.2, -34.35, 140.0, -35.00] |
Pagination
Probably needs to be incorporated into the broader topic rather than being a stand alone entity. Perhaps put the initial explanation the first relevant section.
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Pagination is meant to be used as a data discovery tool (quickly returning small chunks of data). Completeness cannot be guaranteed due to database design and implemented limits (only the first 10,000 elements of the whole subset can be retrieved). If you desire to retrieve more than 10,000 elements, please remove pagination to get all elements. |
The EcoPlots API allows users to paginate their data request in order to retrieve small chunks of data at a time. This is great to discover the data, to inspect the shape of the response and to adjust the desired query to narrow the result subset.
In order to control the amount of computational resources needed to paginate over millions of elements, a limit of 10,000 has been established. This means that even if the count of the query (i.e., the total amount of elements) is greater than 10,000, you will be only able to paginate over and retrieve the first 10,000.
Once the query has been defined, you can remove pagination to retrieve the full set of elements.
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{
"page_number": 1,
"page_size": 50,
"query": {
"dataset": [
"http://linked.data.gov.au/dataset/ausplots"
],
"feature_type": [
"http://linked.data.gov.au/def/tern-cv/b311c0d3-4a1a-4932-a39c-f5cdc1afa611"
],
"observed_property": [
"http://linked.data.gov.au/def/tern-cv/0bbd7fcd-0782-4efc-96e6-1f0f7669c655"
]
}
} |
Adding pagination to your request is as easy as include the “page_number” and “page_size” parameters to the request body.
Response headers are returned with information about the pagination:
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Pagination-Page: 1
Pagination-Size: 50
Pagination-Limit: 200 # Max number of page available. Notice that it could be smaller than the real number of pages due to the 10,000 limitation.
Pagination-Count: 11827 # Total amount of elements |
Request example:
] |
For more information about how to create search queries, please refer to EcoPlots API - autogenerating queries and EcoPlots API - Example search queries.