writeResults {redland}

Write query results to a file.

Description

Write query results to a file.

Usage

writeResults(.Object, model, ...)

## S4 method for signature 'Query'
writeResults(
  .Object,
  model,
  file,
  mimeType = "application/x-turtle",
  format_uri = NULL,
  base_uri = NULL
)

Arguments

.Object

a Query object

model

a Model object

...

additional parameters

file

a string specifying the output file

mimeType

a string specifying the mimeType of the output file. Currently supported values are "application/x-turtle", "text/plain", "application/json", "text/html"

format_uri

(not currently used)

base_uri

(not currently used)

Details

After this method is called, the Query object is no longer usable and should be deleted "rm(query)" and a new object created.

Examples

world <- new("World")
storage <- new("Storage", world, "hashes", name="", options="hash-type='memory'")
model <- new("Model", world, storage, options="")
stmt <- new("Statement", world=world, 
  subject="https://orcid.org/0000-0002-2192-403X",
  predicate="http://www.w3.org/ns/prov#Agent",
  object="slaughter", 
  objectType="literal", datatype_uri="http://www.w3.org/2001/XMLSchema#string")
status <- addStatement(model, stmt)
queryString <- paste("PREFIX orcid: <https://orcid.org/>",
                     "PREFIX dataone: <https://cn.dataone.org/cn/v1/resolve/>",
                     "PREFIX prov: <http://www.w3.org/ns/prov#>",
                     "SELECT ?a ?c WHERE { ?a prov:Agent ?c . }", sep=" ")
query <- new("Query", world, queryString, base_uri=NULL, query_language="sparql", query_uri=NULL)
# Return all results as a string
tf <- tempfile()
writeResults(query, model, file=tf, mimeType="application/x-turtle")

# When the query object is no longer needed, the resources it had allocated can be freed.
freeQuery(query)
rm(query)