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compile_query

Function compile_query 

Source
pub fn compile_query(
    query: &Query,
    stats: &Stats,
    caps: &Capabilities,
    options: &QueryOptions,
) -> Result<CompiledQuery>
Expand description

Compiles a SPARQL query to SQL. Returns Error::Unsupported for anything that cannot be expressed in SQL on this backend.

Examples found in repository?
examples/../tests/golden/dump.rs (line 100)
62pub fn dump(root: &Path) -> Vec<String> {
63    let backends = [
64        ("native", Capabilities::native()),
65        ("d1", Capabilities::d1()),
66    ];
67    let mut paths = Vec::new();
68    for sub in ["sparql10", "sparql11", "sparql12"] {
69        files(&root.join(sub), &mut paths);
70    }
71    paths.sort();
72    let mut out = Vec::new();
73    let options = QueryOptions::default();
74    let stats = Stats::default();
75    for p in &paths {
76        let Ok(text) = std::fs::read_to_string(p) else {
77            continue;
78        };
79        // How `\u` escapes parse depends on spargebra's `standard-unicode-escaping` feature, which
80        // workspace builds enable (for the W3C runner): leave those files out, so the rendering
81        // depends on the compiler alone.
82        if text.contains("\\u") || text.contains("\\U") {
83            continue;
84        }
85        let rel = p.strip_prefix(root).unwrap().display().to_string();
86        let parser = || {
87            SparqlParser::new()
88                .with_base_iri("http://example.com/base/")
89                .unwrap()
90        };
91        let is_update = p.extension().and_then(|x| x.to_str()) == Some("ru");
92        for (name, caps) in &backends {
93            let render = || -> Option<String> {
94                Some(if is_update {
95                    match plan_update(&parser().parse_update(&text).ok()?, caps) {
96                        Ok(plan) => explain_plan(&plan),
97                        Err(e) => format!("ERR {e}"),
98                    }
99                } else {
100                    match compile_query(&parser().parse_query(&text).ok()?, &stats, caps, &options)
101                    {
102                        Ok(c) => c.explain(),
103                        Err(e) => format!("ERR {e}"),
104                    }
105                })
106            };
107            let Some(first) = render() else { continue };
108            // Updates creating fresh blank nodes embed random ids: record that they vary.
109            let h = if render().map(|r| hash(&r)) == Some(hash(&first)) {
110                hash(&first)
111            } else {
112                "varies".to_owned()
113            };
114            out.push(format!("{rel}\t{name}\t{h}"));
115        }
116    }
117    // The batch writer: inserts and deletes of a fixed set of quads.
118    let ex = |s: String| oxrdf::NamedNode::new_unchecked(format!("http://example.com/{s}"));
119    let quads: Vec<oxrdf::Quad> = (0..700)
120        .map(|i| {
121            oxrdf::Quad::new(
122                ex(format!("s{i}")),
123                ex(format!("p{}", i % 7)),
124                oxrdf::Literal::new_simple_literal(format!("value {i}")),
125                if i % 3 == 0 {
126                    oxrdf::GraphName::DefaultGraph
127                } else {
128                    ex(format!("g{}", i % 5)).into()
129                },
130            )
131        })
132        .collect();
133    let enc = EncodedQuads::new(quads.iter().map(oxrdf::Quad::as_ref));
134    for (name, caps) in &backends {
135        let ins: Vec<String> = enc
136            .insert_statements(caps)
137            .into_iter()
138            .map(|s| s.sql)
139            .collect();
140        let del: Vec<String> = enc
141            .delete_statements(caps)
142            .into_iter()
143            .map(|s| s.sql)
144            .collect();
145        out.push(format!("writer/insert\t{name}\t{}", hash(&ins.join("\n"))));
146        out.push(format!("writer/delete\t{name}\t{}", hash(&del.join("\n"))));
147    }
148    out
149}