How to handle sparql duplicate specific values?

@rollin 

There are a few ways to handle duplicate specific values in SPARQL queries:

1. Use the DISTINCT keyword: You can use the DISTINCT keyword in your SELECT query to retrieve only distinct values for a specific variable. This will eliminate duplicate values in the query result.

Example:

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SELECT DISTINCT ?name
WHERE {
  ?person a foaf:Person .
  ?person foaf:name ?name .
}

1. Use the GROUP BY clause: You can use the GROUP BY clause in your query to group results by a specific variable. This can help to aggregate duplicate values and perform calculations on them if needed.

Example:

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SELECT ?name (COUNT(?name) AS ?count)
WHERE {
  ?person a foaf:Person .
  ?person foaf:name ?name .
}
GROUP BY ?name

1. Use FILTER: You can use the FILTER keyword in your query to filter out duplicate values based on specific conditions. This can be useful if you want to eliminate duplicates based on certain criteria.

Example:

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SELECT ?name
WHERE {
  ?person a foaf:Person .
  ?person foaf:name ?name .
}
FILTER NOT EXISTS {
  ?person2 a foaf:Person .
  ?person2 foaf:name ?name .
  FILTER (?person != ?person2)
}

These are some ways to handle duplicate specific values in SPARQL queries. Choose the method that best suits your requirements and the complexity of your data.