Write query results to a file.
Usage
writeResults(.Object, model, ...)
# S4 method for class '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")
#> [1] 0
# When the query object is no longer needed, the resources it had allocated can be freed.
freeQuery(query)
#> NULL
rm(query)