grafter.db.triplestore.query — io.github.swirrl/grafter.db 0.10.0

defquery clj macro

(defquery var-name sparql-resource args-vector)

(defquery var-name sparql-resource args-vector {:keys [reasoning?] :as opts})

Define a function named var-name for running a sparql query via grafter-2.rdf4j/sparql that is defined in the given sparql-resource file. The symbols used for argument are expected to map directly to variables in the query.

• :reasoning? true|false whether or not reasoning/inference should be used in the query. DEFAULT: false

e.g. for a SPARQL resource-file containing the query:

SELECT * WHERE { ?s ?p ?o }

The declaration should contain keywords defining the variables you wish to bind. e.g.:

(defquery select-spo "sparql/select-spo.sparql" [:s])

Then to select ?p & ?o on an http://s pass a bindings map of SPARQL var name to its val:

(select-spo {:s (URI. "http://s")})

Special namespaced keyword bindings can be supplied for limits & offsets:

• :grafter-2.rdf4j.sparql/limits
• :grafter-2.rdf4j.sparql/offsets

::sp/limits and ::sp/offsets both take a map of of limits that correspond to the overrides in the query. For example with the query:

SELECT * WHERE { SELECT ?s WHERE { ?s ?p ?o . } LIMIT 10 } LIMIT 1

We can override both the inner and outer limits by specifying a value of:

{::sp/limits {10 100 ;; override inner limit with 100 1 1000 ;; override outer limit with 1000 }}

Generated query functions take an optional map of options as their last parameter. Valid options are:

• :evaluation-method a keyword for the evaluation function (see get-query-fn)

NOTE also that SPARQL variables ?snake_style variable can be referenced with clojure-style-kebab-case names.

EvaluationMethod clj protocol

evaluation-method clj

(evaluation-method this)

generate-bindings clj

(generate-bindings args-vector)

get-query-fn clj multimethod

keyname clj

(keyname key)

For namespaced keywords, (name) only returns the keyword part. This function returns the namespace and keyword

kmap clj

(kmap f m)

update all keys in a hash-map with function

rename-binding clj

(rename-binding binding)

Rename clojure style hyphenated variable-bindings to sparql style underscored_bindings. Exclude ::sp/limits and ::sp/offsets.

wrap-caching clj

(wrap-caching query-fn)

wrap-eager-evaluation clj

(wrap-eager-evaluation query-fn)