80 lines
2.5 KiB
JavaScript
80 lines
2.5 KiB
JavaScript
// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this
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// file, You can obtain one at http://mozilla.org/MPL/2.0/.
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var datomish = require("../../target/release-node/datomish.js");
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var schema = {
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"name": "pages",
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"attributes": [
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{"name": "page/url",
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"type": "string",
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"cardinality": "one",
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"unique": "identity",
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"doc": "A page's URL."},
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{"name": "page/title",
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"type": "string",
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"cardinality": "one",
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"doc": "A page's title."}
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]
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};
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async function testOpen() {
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// Open a database.
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let db = await datomish.open("/tmp/testing.db");
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// Make sure we have our current schema.
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await db.ensureSchema(schema);
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// Add some data. Note that we use a temporary ID (the real ID
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// will be assigned by Datomish).
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let txResult = await db.transact([
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{"db/id": datomish.tempid(),
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"page/url": "https://mozilla.org/",
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"page/title": "Mozilla"}
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]);
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console.log("Transaction returned " + JSON.stringify(txResult));
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console.log("Transaction instant: " + txResult.txInstant);
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// A simple query.
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let results = await db.q("[:find ?url :in $ :where [?e :page/url ?url]]");
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results = results.map(r => r[0]);
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console.log("Query results: " + JSON.stringify(results));
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// Let's extend our schema. In the real world this would typically happen
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// across releases.
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schema.attributes.push({"name": "page/visitedAt",
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"type": "instant",
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"cardinality": "many",
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"doc": "A visit to the page."});
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await db.ensureSchema(schema);
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// Now we can make assertions with the new vocabulary about existing
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// entities.
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// Note that we simply let Datomish find which page we're talking about by
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// URL -- the URL is a unique property -- so we just use a tempid again.
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await db.transact([
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{"db/id": datomish.tempid(),
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"page/url": "https://mozilla.org/",
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"page/visitedAt": (new Date())}
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]);
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// When did we most recently visit this page?
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let date = (await db.q(
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`[:find (max ?date)
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:in $ ?url
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:where
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[?page :page/url ?url]
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[?page :page/visitedAt ?date]]`,
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{"inputs": {"url": "https://mozilla.org/"}}))[0][0];
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console.log("Most recent visit: " + date);
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// Close: we're done!
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await db.close();
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}
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testOpen()
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.then((r) => console.log("Done."))
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.catch((e) => console.log("Failure: " + e.stack));
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