Wikidata:SPARQL query service/Query Helper

From Wikidata
Jump to: navigation, search

Query Helper allows you to modify an existing query without knowing SPARQL.

When working with the tool it will modify the SPARQL query, based on the input you provide in the visual interface, and vice versa.

It is displayed on the right side of the query editor.

Query Helper

Current limitations[edit]

This is an experimental tool and may break your SPARQL query.

  • JSON serialization should not contain new lines.
  • Template can be placed anywhere in the query: at the top, at the bottom for example.
  • The content of the template will be added to the URL of the query. Some issues may occurs for that reason.

Modify Query[edit]

Query Helper - Edit 'Cat Query'

This section will show how you can edit a query with the Query Helper

Change 'cat' to 'zoo'[edit]

  1. Select the 'Cat Query' from the examples
  2. Click on 'cat' to modify the value
  3. Click on the combo box and enter 'zoo'
  4. Select the 'zoo (Q43501)' item from the combo box

The query will now find items that have 'instance of zoo' instead of 'instance of cat'

Add 'country Germany' filter[edit]

  1. Click on 'Find' button
  2. Enter 'Germany'
  3. Select 'Germany (Q183)'
  4. Click on 'instance of' from 'instance of Germany' to modify the value
  5. Click on the select box and enter 'Country'
  6. Select country (P17) item

The query will now only find items that have 'instance of zoo' and 'country Germany'

Add 'inception' and 'image' columns[edit]

  1. Click on 'Show' button
  2. Enter 'inception'
  3. Select 'inception (P571)' item
  4. Click on 'Show' button
  5. Enter 'image'
  6. Select 'image (P18)'

The query result now has two additional columns 'image' and 'inception' and can be displayed as a Timeline or Image Grid.

Query Template[edit]

Use a Query Template[edit]

Query Helper - Query Template

Queries that have a Query Template defined will show the defined textual representation of this query inside of the Query Helper.

Blue items in this textual representation can be clicked to modify them.

Defined suggestions will be shown or a text can be entered to search for a replacement.

When selecting one of the items in the list it will replace the item in the textual representation and the SPARQL query.

You can find all the queries in the Query Examples List that have a defined Query Template by searching for '#template'.

Create a Query Template[edit]

Query templates can be created by providing a template definition. Here is an example query with a template definition.

The definition is expressed in JSON and inserted as SPARQL comment to the query like this:

#TEMPLATE=[JSON_DEFINITION]

JSON definition example:

{
  "template": "Largest ?c with ?sex head of government",
  "variables": {
    "?sex": {},
    "?c": {
      "query": "SELECT DISTINCT ?id WHERE {  ?c wdt:P31 ?id.  ?c p:P6 ?mayor. }"
    }
  }
}
Key Value Example Description SPARQL Query
template This text will be shown to the user as description for the query.

In the text you can define variables that will be replaced by actual values.

Largest ?c with ?sex head of government This will define two variables within the text:

?c and ?sex

The values for this variables must be defined

in the SPARQL query.

BIND(wd:Q6581072 AS ?sex)

BIND(wd:Q515 AS ?c)
variables In this section you have to define the variables from the template.

You can optionally define a SPARQL query that is used for suggesting values for that variable.

"?sex": {},
"?c": {
  "query": "[SPARQL]"
}
This will define two variables:

?c and ?sex

For the variable ?c there is a SPARQL query defined that will suggest Items.

SELECT DISTINCT ?id WHERE
{ ?c wdt:P31 ?id.?c p:P6 ?mayor. }
The SPARQL query from the Query Template will be embedded into this query to display the result with label, description. If ?count is provided then it will be sorted by desc(?count):
SELECT ?id ?label ?description WITH {				 

[QUERY]		

} AS %inner			
WHERE {	
INCLUDE %inner				
?id rdfs:label ?label.				
?id schema:description ?description.				
FILTER((LANG(?label)) = "en")				
FILTER((LANG(?description)) = "en")			} 
ORDER BY DESC(?count)			
LIMIT 20