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├── .gitignore ├── COPYRIGHT ├── README.md ├── epl-v10.html ├── pom.xml ├── script └── ci_build └── src ├── PrintSchema.java ├── java ├── datomic │ └── samples │ │ ├── Aggregates.java │ │ ├── BuildingQueries.java │ │ ├── CompareAndSwap.java │ │ ├── ComponentAttributes.java │ │ ├── DatabaseFiltering.java │ │ ├── Fns.java │ │ ├── IO.java │ │ ├── MaybeQuery.java │ │ ├── PrettyPrint.java │ │ ├── Pull.java │ │ ├── Query.java │ │ ├── QueryAsData.java │ │ ├── Schema.java │ │ ├── Trust.java │ │ ├── TxFunctions.java │ │ ├── TxReportWatcher.java │ │ └── With.java └── hornet │ └── samples │ ├── PingConsumer.java │ └── PingProducer.java └── resources ├── datomic-java-examples ├── accounts.edn ├── bigger-than-pluto.edn ├── seattle-data0.edn ├── seattle-data1.edn ├── seattle-schema.edn ├── social-news.edn ├── story-with-comments.edn └── stuarts.edn └── logback.xml /.gitignore: -------------------------------------------------------------------------------- 1 | target/* 2 | .idea/* 3 | log/ 4 | *.swp 5 | -------------------------------------------------------------------------------- /COPYRIGHT: -------------------------------------------------------------------------------- 1 | Copyright (c) Metadata Partners, LLC. All rights reserved. 2 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | ## Datomic Java Examples 2 | 3 | Code examples for [Datomic's Java API](https://docs.datomic.com/on-prem/javadoc/index.html). 4 | 5 | ## Questions, Feedback? 6 | 7 | For specific feedback on the examples, please create an 8 | [issue](https://github.com/Datomic/datomic-java-examples/issues). 9 | 10 | For questions about Datomic, try the [public mailing 11 | list](http://groups.google.com/group/datomic). 12 | 13 | ## Contributing 14 | 15 | This library is developed internally by Cognitect. Issues can be filed using 16 | [Github Issues](https://github.com/Datomic/datomic-java-examples/issues). We do 17 | not accept pull request or patches. 18 | 19 | ## License 20 | 21 | EPL. See epl-v10.html at the project root. 22 | -------------------------------------------------------------------------------- /epl-v10.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | Eclipse Public License - Version 1.0 8 | 25 | 26 | 27 | 28 | 29 | 30 |

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258 | 259 | 260 | 261 | 262 | -------------------------------------------------------------------------------- /pom.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | com.datomic 7 | datomic-free 8 | 0.9.5350 9 | 10 | 11 | org.slf4j 12 | slf4j-log4j12 13 | 14 | 15 | org.slf4j 16 | slf4j-nop 17 | 18 | 19 | 20 | 21 | ch.qos.logback 22 | logback-classic 23 | 1.0.1 24 | 25 | 26 | 0.0 27 | com.datomic 28 | datomic-java-examples 29 | datomic-java-examples 30 | 31 | UTF-8 32 | 33 | 4.0.0 34 | 35 | 36 | 37 | 38 | org.apache.maven.plugins 39 | maven-compiler-plugin 40 | 3.0 41 | 42 | 43 | 44 | 45 | 46 | 47 | src/java 48 | 49 | 50 | src/resources 51 | 52 | 53 | 54 | 55 | 56 | Datomic 57 | Datomic 58 | http://files.datomic.com/maven 59 | 60 | true 61 | 62 | 63 | false 64 | 65 | 66 | 67 | Sonatype 68 | Sonatype Release 69 | http://oss.sonatype.org/content/repositories/releases 70 | 71 | true 72 | 73 | 74 | false 75 | 76 | 77 | 78 | jboss 79 | https://repository.jboss.org/nexus/content/groups/public 80 | 81 | true 82 | 83 | 84 | false 85 | 86 | 87 | 88 | clojars.org 89 | http://clojars.org/repo 90 | 91 | 92 | clojure-releases 93 | http://build.clojure.org/releases 94 | 95 | true 96 | 97 | 98 | false 99 | 100 | 101 | 102 | 103 | -------------------------------------------------------------------------------- /script/ci_build: -------------------------------------------------------------------------------- 1 | #!/bin/bash -x 2 | 3 | set -e 4 | 5 | classes=( 6 | Aggregates 7 | BuildingQueries 8 | CompareAndSwap 9 | ComponentAttributes 10 | DatabaseFiltering 11 | Query 12 | QueryAsData 13 | Trust 14 | With 15 | ) 16 | 17 | mvn package 18 | 19 | for class in "${classes[@]}" 20 | do 21 | mvn exec:java -Dexec.mainClass="datomic.samples.${class}" 22 | done 23 | -------------------------------------------------------------------------------- /src/PrintSchema.java: -------------------------------------------------------------------------------- 1 | /** 2 | * Datomic example code 3 | */ 4 | 5 | import datomic.Entity; 6 | import datomic.Connection; 7 | import datomic.Database; 8 | 9 | import java.util.Collection; 10 | import java.util.Iterator; 11 | import java.util.List; 12 | import java.util.Set; 13 | import java.util.Map; 14 | 15 | import static datomic.Peer.connect; 16 | import static datomic.Peer.createDatabase; 17 | import static datomic.Peer.q; 18 | 19 | public class PrintSchema { 20 | /** 21 | * Print an entity 22 | */ 23 | public static void printEntity(Entity e) { 24 | Set keys = e.keySet(); 25 | for (Iterator iterator = keys.iterator(); iterator.hasNext();) { 26 | Object key = iterator.next(); 27 | System.out.println(key + " = " + e.get(key)); 28 | } 29 | } 30 | 31 | /** 32 | * Print results from a query that returns entities in 1-tuples. 33 | * @param tuples 34 | */ 35 | public static void printEntities(Collection> tuples) { 36 | for (Iterator> iterator = tuples.iterator(); iterator.hasNext();) { 37 | System.out.println(); 38 | printEntity((Entity) iterator.next().get(0)); 39 | } 40 | } 41 | 42 | /** 43 | * Schemas are plain data, like everything else. Values of 44 | * :db.install/attribute are the attributes defined in the schema. 45 | * @param db 46 | */ 47 | public static void printAttributeSchema(Database db) { 48 | Collection> tuples = q("[:find ?entity" + 49 | " :where [_ :db.install/attribute ?v]" + 50 | "[(.entity $ ?v) ?entity]]", 51 | db); 52 | printEntities(tuples); 53 | } 54 | 55 | public static void main(String[] args) { 56 | String uri = "datomic:mem://db"; 57 | createDatabase(uri); 58 | Connection conn = connect(uri); 59 | 60 | String query = "[:find ?entity " + 61 | ":in $ ?s " + 62 | ":where [?e :db/valueType]" + 63 | "[?e :db/ident ?a]" + 64 | "[(namespace ?a) ?ns]" + 65 | "[(= ?ns ?s)]" + 66 | "[(.entity $ ?e) ?entity]]"; 67 | Collection> results = q(query,conn.db(),"db"); 68 | printEntities(results); 69 | // printAttributeSchema(conn.db()); 70 | } 71 | } 72 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Aggregates.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | 6 | import java.io.IOException; 7 | 8 | import static datomic.Peer.query; 9 | import static datomic.samples.Fns.scratchConnection; 10 | import static datomic.samples.IO.transactAllFromResource; 11 | import static datomic.samples.PrettyPrint.print; 12 | 13 | public class Aggregates { 14 | 15 | public static void main(String[] args) throws IOException { 16 | Connection conn = scratchConnection(); 17 | transactAllFromResource(conn, "datomic-java-examples/bigger-than-pluto.edn"); 18 | Database db = conn.db(); 19 | 20 | print(biggestObjectRadius(db)); 21 | print(randomObject(db)); 22 | print(sampleFiveObjects(db)); 23 | 24 | } 25 | 26 | public static Object biggestObjectRadius(Database db) { 27 | return query("[:find (max ?radius) ." + 28 | " :where [_ :object/meanRadius ?radius]]", db); 29 | } 30 | 31 | public static Object randomObject(Database db) { 32 | return query("[:find (rand ?name) ." + 33 | " :where [?e :object/name ?name]]", db); 34 | } 35 | 36 | public static Object sampleFiveObjects(Database db) { 37 | return query("[:find (sample 5 ?name) ." + 38 | " :with ?e" + 39 | " :where [?e :object/name ?name]]", db); 40 | } 41 | } 42 | -------------------------------------------------------------------------------- /src/java/datomic/samples/BuildingQueries.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | 6 | import java.io.IOException; 7 | import java.io.InputStreamReader; 8 | import java.net.URL; 9 | import java.util.Collection; 10 | import java.util.List; 11 | 12 | import static datomic.Peer.query; 13 | import static datomic.Util.list; 14 | import static datomic.samples.Fns.scratchConnection; 15 | import static datomic.samples.IO.resource; 16 | import static datomic.samples.IO.transactAll; 17 | import static datomic.samples.IO.transactAllFromResource; 18 | import static datomic.samples.PrettyPrint.print; 19 | 20 | public class BuildingQueries { 21 | 22 | public static void queryWithVariableBinding(Database db) { 23 | print(query("[:find [?e ...]" + 24 | " :in $ ?name" + 25 | " :where [?e :user/firstName ?name]]", 26 | db, "Stewart")); 27 | } 28 | 29 | public static void queryWithCollectionBinding(Database db) { 30 | print(query("[:find [?e ...]" + 31 | " :in $ [?name ...]" + 32 | " :where [?e :user/firstName ?name]]", 33 | db, list("Stewart", "Stuart"))); 34 | } 35 | 36 | public static void queryWithMultipleCollectionBindings(Database db) { 37 | print(query("[:find [?e ...]" + 38 | " :in $ [?name ...] [?attr ...]" + 39 | " :where [?e ?attr ?name]]", 40 | db, list("Stuart", "Stewart"), list(":user/firstName", ":user/lastName"))); 41 | } 42 | 43 | public static void queryWithMapForm(Database db) { 44 | print(query("{:find [[?e ...]]" + 45 | " :in [$ ?fname ?lname]" + 46 | " :where [[?e :user/firstName ?fname]" + 47 | " [?e :user/lastName ?lname]]}", 48 | db, "Stuart", "Smalley")); 49 | } 50 | 51 | public static void main(String[] args) throws IOException { 52 | Connection conn = scratchConnection(); 53 | transactAllFromResource(conn, "datomic-java-examples/social-news.edn"); 54 | transactAllFromResource(conn, "datomic-java-examples/stuarts.edn"); 55 | Database db = conn.db(); 56 | 57 | queryWithVariableBinding(db); 58 | queryWithCollectionBinding(db); 59 | queryWithMultipleCollectionBindings(db); 60 | queryWithMapForm(db); 61 | } 62 | } 63 | -------------------------------------------------------------------------------- /src/java/datomic/samples/CompareAndSwap.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import static datomic.Connection.*; 5 | 6 | import datomic.Database; 7 | import datomic.ListenableFuture; 8 | import datomic.Peer; 9 | 10 | import java.io.IOException; 11 | import java.io.InputStreamReader; 12 | import java.net.URL; 13 | import java.util.Map; 14 | import java.util.concurrent.ExecutionException; 15 | 16 | import static datomic.Util.*; 17 | 18 | import static datomic.samples.Fns.scratchConnection; 19 | import static datomic.samples.IO.resource; 20 | import static datomic.samples.IO.transactAll; 21 | import static datomic.Peer.tempid; 22 | 23 | public class CompareAndSwap { 24 | public static void main(String[] args) throws IOException, InterruptedException, ExecutionException { 25 | Connection conn = scratchConnection(); 26 | URL url = resource("datomic-java-examples/accounts.edn"); 27 | transactAll(conn, new InputStreamReader(url.openStream())); 28 | 29 | Object account = tempid(":db.part/user"); 30 | Map txResult = conn.transact(list(map(":db/id", account, ":account/balance", 100))).get(); 31 | account = Peer.resolveTempid((Database)txResult.get(DB_AFTER), txResult.get(TEMPIDS), account); 32 | 33 | System.out.println("CAS from 100->110 should succeed"); 34 | conn.transact(list(list(":db.fn/cas", account, ":account/balance", 100, 110))).get(); 35 | 36 | System.out.println("CAS from 100->120 should fail"); 37 | try { 38 | conn.transact(list(list(":db.fn/cas", account, ":account/balance", 100, 120))).get(); 39 | } catch (Throwable t) { 40 | System.out.println("Failed with " + t.getMessage()); 41 | } 42 | 43 | System.out.println("Balance is " + conn.db().entity(account).get(":account/balance")); 44 | 45 | } 46 | } 47 | -------------------------------------------------------------------------------- /src/java/datomic/samples/ComponentAttributes.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | 4 | import datomic.Connection; 5 | import datomic.Database; 6 | import datomic.Datom; 7 | 8 | import java.io.IOException; 9 | import java.util.*; 10 | import java.util.concurrent.ExecutionException; 11 | 12 | import static datomic.Util.list; 13 | import static datomic.Connection.TX_DATA; 14 | import static datomic.samples.Fns.scratchConnection; 15 | import static datomic.samples.IO.transactAllFromResource; 16 | 17 | public class ComponentAttributes { 18 | public static void main(String[] args) throws IOException, ExecutionException, InterruptedException { 19 | Connection conn = scratchConnection(); 20 | transactAllFromResource(conn, "datomic-java-examples/social-news.edn"); 21 | transactAllFromResource(conn, "datomic-java-examples/story-with-comments.edn"); 22 | Database db = conn.db(); 23 | 24 | System.out.println("\nTouch an entity with componeont attributes..."); 25 | System.out.println(db.entity(":storyWithComments").touch()); 26 | 27 | System.out.println("\nDoc string for :db.fn/retractEntity..."); 28 | System.out.println(db.entity(":db.fn/retractEntity").touch()); 29 | 30 | Collection datoms = 31 | (Collection) conn.transact(list(list(":db.fn/retractEntity", ":storyWithComments"))) 32 | .get() 33 | .get(TX_DATA); 34 | Set retractedEs = new HashSet(); 35 | for (Iterator iterator = datoms.iterator(); iterator.hasNext(); ) { 36 | Datom datom = iterator.next(); 37 | if (!datom.added()) retractedEs.add(datom.e()); 38 | } 39 | 40 | System.out.println("\nRetracted entities " + retractedEs); 41 | } 42 | } 43 | -------------------------------------------------------------------------------- /src/java/datomic/samples/DatabaseFiltering.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.*; 4 | 5 | import java.io.IOException; 6 | import java.io.InputStreamReader; 7 | import java.net.URL; 8 | import java.util.concurrent.ExecutionException; 9 | 10 | import static datomic.Util.list; 11 | import static datomic.Util.map; 12 | import static datomic.samples.Fns.scratchConnection; 13 | import static datomic.samples.IO.resource; 14 | import static datomic.samples.IO.transactAll; 15 | 16 | import static datomic.Peer.*; 17 | 18 | public class DatabaseFiltering { 19 | public static Object tempid() { 20 | return Peer.tempid(":db.part/user"); 21 | } 22 | 23 | public static final String storyQuery = "[:find (count ?e) :where [?e :story/url]]"; 24 | 25 | public static void main(String[] args) throws IOException, ExecutionException, InterruptedException { 26 | Connection conn = scratchConnection(); 27 | URL url = resource("datomic-java-examples/social-news.edn"); 28 | transactAll(conn, new InputStreamReader(url.openStream())); 29 | Database db = conn.db(); 30 | 31 | System.out.print("\nTotal number of stories: "); 32 | System.out.println(q(storyQuery, db)); 33 | 34 | System.out.print("\nTotal number of published stories: "); 35 | System.out.println(q(storyQuery, db.filter(new Database.Predicate() { 36 | public boolean apply(Database db, Datom datom) { 37 | return db.entity(datom.tx()).get(":publish/at") != null; 38 | } 39 | }))); 40 | } 41 | } 42 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Fns.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | 4 | import datomic.Peer; 5 | 6 | import datomic.Connection; 7 | import java.util.Collection; 8 | import java.util.Iterator; 9 | import java.util.UUID; 10 | 11 | public class Fns { 12 | /** 13 | * Connection to a fresh in-memory Datomic database. 14 | * @return 15 | */ 16 | public static Connection scratchConnection() { 17 | String uri = "datomic:mem://" + UUID.randomUUID(); 18 | Peer.createDatabase(uri); 19 | return Peer.connect(uri); 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/java/datomic/samples/IO.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Util; 5 | 6 | import java.io.IOException; 7 | import java.io.InputStreamReader; 8 | import java.io.Reader; 9 | import java.net.URI; 10 | import java.net.URL; 11 | import java.util.Iterator; 12 | import java.util.List; 13 | import java.util.concurrent.ExecutionException; 14 | 15 | public class IO { 16 | public static void transactAll(Connection conn, Reader reader) { 17 | List txes = Util.readAll(reader); 18 | for (java.util.Iterator it = txes.iterator(); it.hasNext(); ) { 19 | List tx = it.next(); 20 | try { 21 | conn.transact(tx).get(); 22 | } catch (Exception e) { 23 | throw new RuntimeException(e); 24 | } 25 | } 26 | } 27 | 28 | public static URL resource(String name) { 29 | return Thread.currentThread().getContextClassLoader().getResource(name); 30 | } 31 | 32 | public static void transactAllFromResource(Connection conn, String resource) { 33 | URL url = resource(resource); 34 | try { 35 | transactAll(conn, new InputStreamReader(url.openStream())); 36 | } catch (Exception e) { 37 | throw new RuntimeException(e); 38 | } 39 | } 40 | 41 | } 42 | -------------------------------------------------------------------------------- /src/java/datomic/samples/MaybeQuery.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | 6 | import java.util.*; 7 | 8 | import static datomic.Peer.*; 9 | import static datomic.Util.read; 10 | import static datomic.samples.Fns.scratchConnection; 11 | import static datomic.samples.Schema.CARDINALITY_MANY; 12 | import static datomic.samples.Schema.CARDINALITY_ONE; 13 | import static datomic.samples.Schema.cardinality; 14 | 15 | public class MaybeQuery { 16 | 17 | /** 18 | * Function intended for use inside a Datomic query 19 | * 20 | * @param db a database value 21 | * @param e an entity id 22 | * @param attr an attribute 23 | * @param ifNot value to return if attribute absent 24 | * @return attribute value, set of attribute values, or ifNot, depending 25 | * on cardinality of the attribute, and whether any values are present 26 | */ 27 | public static Object maybe(Object db, Object e, Object attr, Object ifNot) { 28 | Collection> result = query("[:find ?v " + 29 | ":in $ ?e ?a " + 30 | ":where [?e ?a ?v]]", db, e, attr); 31 | if (result.isEmpty()) { 32 | return ifNot; 33 | } else { 34 | Object card = cardinality(db, attr); 35 | if (card.equals(CARDINALITY_ONE)) return result.iterator().next(); // only one in list 36 | Set acc = new HashSet(); 37 | for (Iterator> iterator = result.iterator(); iterator.hasNext(); ) { 38 | acc.add(iterator.next()); 39 | } 40 | return Collections.unmodifiableSet(acc); 41 | } 42 | } 43 | 44 | public static String rules = 45 | "[[[attr-in-namespace ?e ?ns2]\n" + 46 | " [?e :db/ident ?a]\n" + 47 | " [?e :db/valueType]\n" + 48 | " [(namespace ?a) ?ns1]\n" + 49 | " [(= ?ns1 ?ns2)]]]"; 50 | 51 | public static void main(String[] args) { 52 | Connection conn = scratchConnection(); 53 | Database db = conn.db(); 54 | 55 | System.out.println("Maybe entity zero has a docstring..."); 56 | System.out.println(maybe(db, 0, read(":db/doc"), "")); 57 | 58 | System.out.println("\nMaybe entity zero has installed some atttributes"); 59 | System.out.println(maybe(db, 0, read(":db.install/attribute"), "")); 60 | 61 | System.out.println("\nMaybe entity one has installed some attributes"); 62 | System.out.println(maybe(db, 1, read(":db.install/attribute"), "")); 63 | 64 | System.out.println("\nMaybe we can call maybe from inside a query"); 65 | System.out.println(q("[:find ?ident ?card" + 66 | " :where [?e :db/ident ?ident]" + 67 | " [(datomic.samples.MaybeQuery/maybe $ ?e :db/cardinality \"\") ?card]]", 68 | db)); 69 | 70 | System.out.println("Look up attributes in the db namespace:"); 71 | System.out.println(q( 72 | "[:find ?e ?ident\n" + 73 | " :in $ %\n" + 74 | " :where\n" + 75 | " (attr-in-namespace ?e \"db\")\n" + 76 | " [?e :db/ident ?ident]]", 77 | db, rules)); 78 | } 79 | } 80 | -------------------------------------------------------------------------------- /src/java/datomic/samples/PrettyPrint.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import clojure.java.api.Clojure; 4 | import clojure.lang.IFn; 5 | 6 | public class PrettyPrint { 7 | public static final IFn prettyPrint = Clojure.var("clojure.pprint", "pprint"); 8 | public static void print(Object o) { 9 | prettyPrint.invoke(o); 10 | } 11 | } 12 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Pull.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | import datomic.Peer; 6 | 7 | import java.util.UUID; 8 | 9 | import static datomic.Util.list; 10 | import static datomic.samples.PrettyPrint.print; 11 | 12 | public class Pull { 13 | public static final Object ledZeppelin = list(":artist/gid", UUID.fromString("678d88b2-87b0-403b-b63d-5da7465aecc3")); 14 | public static final Object mccartney = list(":artist/gid", UUID.fromString("ba550d0e-adac-4864-b88b-407cab5e76af")); 15 | public static final Object darkSideOfTheMoon = list(":release/gid", UUID.fromString("24824319-9bb8-3d1e-a2c5-b8b864dafd1b")); 16 | public static final Object dylanHarrisonSessions = list(":release/gid", UUID.fromString("67bbc160-ac45-4caf-baae-a7e9f5180429")); 17 | public static final Object concertForBanglaDesh = list(":release/gid", UUID.fromString("f3bdff34-9a85-4adc-a014-922eef9cdaa5")); 18 | 19 | public static void main(String[] args) { 20 | Connection conn = Peer.connect("datomic:free://localhost:4334/mbrainz-1968-1973"); 21 | Database db = conn.db(); 22 | 23 | System.out.println("\nPull attribute name"); 24 | print(db.pull("[:artist/name :artist/startYear]", ledZeppelin)); 25 | 26 | System.out.println("\nReverse lookup"); 27 | print(db.pull("[:artist/_country]", ":country/GB")); 28 | 29 | System.out.println("\nComponent Defaults"); 30 | print(db.pull("[:release/media]", darkSideOfTheMoon)); 31 | 32 | Object dylanHarrisonCD = Peer.query( 33 | "[:find ?medium ." + 34 | " :in $ ?release" + 35 | " :where [?release :release/media ?medium]]", 36 | db, dylanHarrisonSessions); 37 | 38 | System.out.println("\nReverse Component Lookup"); 39 | print(db.pull("[:release/_media]", dylanHarrisonCD)); 40 | 41 | long ghostRiders = (Long) Peer.query( 42 | "[:find ?track ." + 43 | " :in $ ?release ?trackno" + 44 | " :where" + 45 | " [?release :release/media ?medium]" + 46 | " [?medium :medium/tracks ?track]" + 47 | " [?track :track/position ?trackno]]", 48 | db, dylanHarrisonSessions, 11); 49 | 50 | System.out.println("\nMap specifications"); 51 | print(db.pull("[:track/name {:track/artists [:db/id :artist/name]}]", ghostRiders)); 52 | 53 | System.out.println("\nNested Map specifications"); 54 | print(db.pull( 55 | "[{:release/media" + 56 | " [{:medium/tracks" + 57 | " [:track/name {:track/artists [:artist/name]}]}]}]", 58 | concertForBanglaDesh)); 59 | 60 | System.out.println("\nWildcard specification"); 61 | print(db.pull("[*]",concertForBanglaDesh)); 62 | 63 | System.out.println("\nWildcard + map specification"); 64 | print(db.pull("[* {:track/artists [:artist/name]}]",ghostRiders)); 65 | 66 | System.out.println("\nDefault expression"); 67 | print(db.pull("[:artist/name (default :artist/endYear 0)]",mccartney)); 68 | 69 | System.out.println("\nDefault expression with different type"); 70 | print(db.pull("[:artist/name (default :artist/endYear \"N/A\")]",mccartney)); 71 | 72 | System.out.println("\nAbsent attributes are omitted from results"); 73 | print(db.pull("[:artist/name :died-in-1966?]",mccartney)); 74 | 75 | System.out.println("\nLimit plus subspec"); 76 | print(db.pull("[{(limit :track/_artists 10) [:track/name]}]",ledZeppelin)); 77 | 78 | System.out.println("\nNo limit"); 79 | print(db.pull("[{(limit :track/_artists nil) [:track/name]}]",ledZeppelin)); 80 | 81 | System.out.println("\nPull expression in query"); 82 | print(Peer.query( 83 | "[:find [(pull ?e [:release/name]) ...]" + 84 | " :in $ ?artist" + 85 | " :where [?e :release/artists ?artist]]", 86 | db, ledZeppelin)); 87 | 88 | System.out.println("\nDynamic pattern input"); 89 | print(Peer.query( 90 | "[:find [(pull ?e pattern) ...]" + 91 | " :in $ ?artist pattern" + 92 | " :where [?e :release/artists ?artist]]", 93 | db, ledZeppelin, "[:release/name]")); 94 | Peer.shutdown(true); 95 | } 96 | } 97 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Query.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.*; 4 | 5 | import java.util.List; 6 | import java.util.Scanner; 7 | import java.util.Collection; 8 | 9 | import static datomic.Util.read; 10 | import static datomic.samples.Fns.scratchConnection; 11 | import static datomic.samples.Schema.CARDINALITY_MANY; 12 | import static datomic.samples.Schema.CARDINALITY_ONE; 13 | import static datomic.samples.Schema.cardinality; 14 | 15 | public class Query { 16 | 17 | public static void main(String[] args) { 18 | 19 | // Your connection information for local mbrainz 1968-1973 subset goes here. 20 | String uri = "datomic:free://localhost:4334/mbrainz-1968-1973"; 21 | 22 | // Connect to transactor, get latest database value from storage. 23 | Connection conn = Peer.connect(uri); 24 | Database db = conn.db(); 25 | 26 | System.out.println("All releases in the database with release names."); 27 | Collection results = Peer.query("[:find ?release-name :where [_ :release/name ?release-name]]", db); 28 | System.out.println(results); 29 | pause(); 30 | 31 | System.out.println("Same as previous query, but with explicit db-var ($)."); 32 | results = Peer.query("[:find ?release-name :in $ :where [$ _ :release/name ?release-name]]", db); 33 | System.out.println(results); 34 | pause(); 35 | 36 | System.out.println("Query that finds releases by artist. Parameterized to accept artist name as an argument."); 37 | results = Peer.query("[:find ?release-name " + 38 | ":in $ ?artist-name " + 39 | ":where [?artist :artist/name ?artist-name] " + 40 | "[?release :release/artists ?artist] " + 41 | "[?release :release/name ?release-name]]", 42 | db, "John Lennon"); 43 | System.out.println(results); 44 | pause(); 45 | 46 | System.out.println("This query accepts a relation argument as a vector and destructures it within the :in."); 47 | results = Peer.query("[:find ?release " + 48 | " :in $ [?artist-name ?release-name] " + 49 | " :where [?artist :artist/name ?artist-name] " + 50 | " [?release :release/artists ?artist] " + 51 | " [?release :release/name ?release-name]]", 52 | db, Util.list("John Lennon", "Mind Games")); 53 | System.out.println(results); 54 | pause(); 55 | 56 | 57 | System.out.println("This query accepts a list of artist arguments and uses destructuring to satisfy the " + 58 | "query for each of them (union of results)."); 59 | results = Peer.query("[:find ?release-name " + 60 | ":in $ [?artist-name ...] " + 61 | ":where [?artist :artist/name ?artist-name] " + 62 | " [?release :release/artists ?artist] " + 63 | " [?release :release/name ?release-name]]", 64 | db, Util.list("Paul McCartney", "George Harrison")); 65 | pause(); 66 | 67 | System.out.println("This query accepts a list of relations, also a list, and destructures the arguments in " + 68 | "the :in clause."); 69 | results = Peer.query("[:find ?release " + 70 | ":in $ [[?artist-name ?release-name]] " + 71 | ":where [?artist :artist/name ?artist-name] " + 72 | " [?release :release/artists ?artist] " + 73 | " [?release :release/name ?release-name]]", 74 | db, Util.list(Util.list("John Lennon", "Mind Games"), 75 | Util.list("Paul McCartney", "Ram"))); 76 | System.out.println(results); 77 | pause(); 78 | 79 | System.out.println("This query returns a collection of relations, all artists and their releases."); 80 | results = Peer.query("[:find ?artist-name ?release-name " + 81 | ":where [?release :release/name ?release-name] " + 82 | " [?release :release/artists ?artist] " + 83 | " [?artist :artist/name ?artist-name]]", 84 | db); 85 | System.out.println(results); 86 | pause(); 87 | 88 | System.out.println("This query returns a list of releases by using a find specification."); 89 | results = Peer.query("[:find [?release-name ...]" + 90 | " :in $ ?artist-name " + 91 | " :where [?artist :artist/name ?artist-name] " + 92 | " [?release :release/artists ?artist] " + 93 | " [?release :release/name ?release-name]]", 94 | db, "John Lennon"); 95 | System.out.println(results); 96 | pause(); 97 | 98 | System.out.println("This query returns values from multiple attributes to provide artist's start date."); 99 | results = Peer.query("[:find [?year ?month ?day] " + 100 | " :in $ ?name " + 101 | " :where [?artist :artist/name ?name] " + 102 | " [?artist :artist/startDay ?day] " + 103 | " [?artist :artist/startMonth ?month] " + 104 | " [?artist :artist/startYear ?year]]", 105 | db, "John Lennon"); 106 | System.out.println(results); 107 | pause(); 108 | 109 | System.out.println("Return just the year of start date using a scalar find specification."); 110 | Long year = Peer.query("[:find ?year . " + 111 | " :in $ ?name " + 112 | " :where [?artist :artist/name ?name] " + 113 | " [?artist :artist/startYear ?year]]", 114 | db, "John Lennon"); 115 | System.out.println(year); 116 | pause(); 117 | 118 | System.out.println("Total number of artists who aren't Canadian."); 119 | Integer res = Peer.query("[:find (count ?eid) . " + 120 | ":where [?eid :artist/name] " + 121 | "(not [?eid :artist/country :country/CA])]", 122 | db); 123 | System.out.println(res); 124 | pause(); 125 | 126 | System.out.println("Use not-join to bind variable in subquery. Artists w/o releases in 1970."); 127 | res = Peer.query("[:find (count ?artist) . " + 128 | ":where [?artist :artist/name] " + 129 | "(not-join [?artist] " + 130 | " [?release :release/artists ?artist] " + 131 | " [?release :release/year 1970])]", 132 | db); 133 | System.out.println(res); 134 | pause(); 135 | 136 | System.out.println("Number of 'Live at Carnegie Hall' releases not by Bill Withers"); 137 | res = Peer.query("[:find (count ?r) . " + 138 | ":where [?r :release/name \"Live at Carnegie Hall\"] " + 139 | "(not-join [?r] " + 140 | "[?r :release/artists ?a] " + 141 | "[?a :artist/name \"Bill Withers\"])]", 142 | db); 143 | System.out.println(res); 144 | pause(); 145 | 146 | System.out.println("Total of artists who are a group or female by use of 'or'."); 147 | res = Peer.query("[:find (count ?artist) . " + 148 | " :where (or [?artist :artist/type :artist.type/group] " + 149 | " (and [?artist :artist/type :artist.type/person] " + 150 | " [?artist :artist/gender :artist.gender/female]))]", 151 | db); 152 | System.out.println(res); 153 | pause(); 154 | 155 | System.out.println("Count of releases from Canadian artists or the year 1970 using 'or-join'"); 156 | res = Peer.query("[:find (count ?release) . " + 157 | " :where [?release :release/name] " + 158 | " (or-join [?release] " + 159 | " (and [?release :release/artists ?artist] " + 160 | " [?artist :artist/country :country/CA]) " + 161 | " [?release :release/year 1970])]", 162 | db); 163 | System.out.println(res); 164 | pause(); 165 | 166 | 167 | System.out.println("Track name and duration in minutes using function call in query."); 168 | results = Peer.query("[:find ?track-name ?minutes " + 169 | ":in $ ?artist-name " + 170 | ":where [?artist :artist/name ?artist-name] " + 171 | " [?track :track/artists ?artist] " + 172 | " [?track :track/duration ?millis] " + 173 | " [(quot ?millis 60000) ?minutes] " + 174 | " [?track :track/name ?track-name]]", 175 | db, "John Lennon"); 176 | System.out.println(results); 177 | pause(); 178 | 179 | // Can't nest expression clauses 180 | String QueryFail = "[:find ?celsius . " + 181 | " :in ?fahrenheit " + 182 | " :where [(/ (- ?fahrenheit 32) 1.8) ?celsius]]"; 183 | Integer QueryFailInput = 212; 184 | 185 | System.out.println("Function calls without nesting:"); 186 | Double celsius = Peer.query("[:find ?celsius . " + 187 | " :in ?fahrenheit " + 188 | " :where [(- ?fahrenheit 32) ?f-32] " + 189 | " [(/ ?f-32 1.8) ?celsius]]", 190 | 212); 191 | System.out.println(celsius); 192 | pause(); 193 | 194 | System.out.println("get-else example:"); 195 | results = Peer.query("[:find ?artist-name ?year " + 196 | " :in $ [?artist-name ...] " + 197 | " :where [?artist :artist/name ?artist-name] " + 198 | " [(get-else $ ?artist :artist/startYear \"N/A\") ?year]]", 199 | db, Util.list("Crosby, Stills & Nash", "Crosby & Nash")); 200 | System.out.println(results); 201 | pause(); 202 | 203 | System.out.println("get-some example:"); 204 | results = Peer.query("[:find [?e ?attr ?name] " + 205 | ":in $ ?e " + 206 | ":where [(get-some $ ?e :country/name :artist/name) [?attr ?name]]]", 207 | db, Util.read(":country/US")); 208 | System.out.println(results); 209 | pause(); 210 | 211 | System.out.println("fulltext example returns info for songs with 'Jane' in the title."); 212 | results = Peer.query("[:find ?entity ?name ?tx ?score " + 213 | " :in $ ?search " + 214 | " :where [(fulltext $ :artist/name ?search) [[?entity ?name ?tx ?score]]]]", 215 | db, "Jane"); 216 | System.out.println(results); 217 | pause(); 218 | 219 | System.out.println("'missing' query finds artists without start year."); 220 | results = Peer.query("[:find ?name " + 221 | " :where [?artist :artist/name ?name] " + 222 | " [(missing? $ ?artist :artist/startYear)]]", 223 | db); 224 | System.out.println(results); 225 | pause(); 226 | 227 | System.out.println("This query finds transactions using the Log API."); 228 | results = Peer.query("[:find [?tx ...] " + 229 | " :in ?log " + 230 | " :where [(tx-ids ?log 1000 1050) [?tx ...]]]", 231 | conn.log()); 232 | System.out.println(results); 233 | pause(); 234 | 235 | System.out.println("This query finds information about a transaction using the Log API."); 236 | results = Peer.query("[:find [?e ...] " + 237 | " :in ?log ?tx " + 238 | " :where [(tx-data ?log ?tx) [[?e]]]]", 239 | conn.log(), 13194139534312L); 240 | System.out.println(results); 241 | pause(); 242 | 243 | 244 | System.out.println("Calling a Java static method in a query."); 245 | results = Peer.query("[:find ?k ?v " + 246 | " :where [(System/getProperties) [[?k ?v]]]]"); 247 | System.out.println(results); 248 | pause(); 249 | 250 | System.out.println("Calling a Java instance method in a query."); 251 | results = Peer.query("[:find ?k ?v " + 252 | " :where [(System/getProperties) [[?k ?v]]]" + 253 | " [(.endsWith ?k \"version\")]]"); 254 | System.out.println(results); 255 | pause(); 256 | 257 | System.out.println("Calling Clojure functions"); 258 | results = Peer.query("[:find [?prefix ...] " + 259 | " :in [?word ...] " + 260 | " :where [(subs ?word 0 5) ?prefix]]", 261 | Util.list("hello", "antidisestablishmentarianism")); 262 | System.out.println(results); 263 | pause(); 264 | 265 | 266 | System.out.println("Attr bound by entity ID, query for ident."); 267 | results = Peer.query("[:find [?aname ...] " + 268 | " :where [?attr 42 _] " + 269 | " [?attr :db/ident ?aname]]", 270 | db); 271 | System.out.println(results); 272 | pause(); 273 | 274 | System.out.println("Avoid dynamic attr. specs unless you really need them."); 275 | // results = Peer.query("[:find [?aname ...] " + 276 | // " :in $ [?property ...] " + 277 | // " :where [?attr ?property _] " + 278 | // " [?attr :db/ident ?aname]]", 279 | // db, Util.read(":db/unique")); 280 | // System.out.println(results); 281 | // pause(); 282 | 283 | System.out.println("The following three queries are equivalent..."); 284 | System.out.println("This one retrieves an entity by lookup ref."); 285 | results = Peer.query("[:find [?artist-name ...] " + 286 | " :in $ ?country" + 287 | " :where [?artist :artist/name ?artist-name] " + 288 | " [?artist :artist/country ?country]]", 289 | db, Util.list(Util.read(":country/name"), "Belgium")); 290 | System.out.println(results); 291 | pause(); 292 | 293 | System.out.println("This one retrieves the same entity by ident."); 294 | results = Peer.query("[:find [?artist-name ...] " + 295 | " :in $ ?country" + 296 | " :where [?artist :artist/name ?artist-name] " + 297 | " [?artist :artist/country ?country]]", 298 | db, Util.read(":country/BE")); 299 | System.out.println(results); 300 | pause(); 301 | 302 | System.out.println("This one retrieves the same entity by its entity ID (Long)"); 303 | results = Peer.query("[:find [?artist-name ...] " + 304 | " :in $ ?country" + 305 | " :where [?artist :artist/name ?artist-name] " + 306 | " [?artist :artist/country ?country]]", 307 | db, 17592186045438L); 308 | System.out.println(results); 309 | pause(); 310 | 311 | System.out.println("This query doesn't work as intended."); 312 | results = Peer.query("[:find [?artist-name ...] " + 313 | " :in $ ?country [?reference ...] " + 314 | " :where [?artist :artist/name ?artist-name] " + 315 | " [?artist ?reference ?country]]", 316 | db, Util.read(":country/BE"), Util.list(Util.read(":artist/country"))); 317 | 318 | System.out.println(results); 319 | pause(); 320 | 321 | System.out.println("We fix it by manually resolving the ident to its entity id."); 322 | // results = Peer.query("[:find [?artist-name ...] " + 323 | // " :in $ ?country [?reference ...] " + 324 | // " :where [(datomic.api/entid $ ?country) ?country-id] " + 325 | // " [?artist :artist/name ?artist-name] " + 326 | // " [?artist ?reference ?country-id]]", 327 | // db, Util.read(":country/BE"), Util.list(Util.read(":artist/country"))); 328 | // System.out.println(results); 329 | // pause(); 330 | 331 | System.out.println("We have to use ':with' to get duplicate values as Datomic query returns sets by default."); 332 | Long heads = Peer.query("[:find (sum ?heads) . " + 333 | " :in [[_ ?heads]]]", 334 | Util.list(Util.list("Cerberus", 3), 335 | Util.list("Cyclops", 1), 336 | Util.list("Medusa", 1), 337 | Util.list("Chimera", 1))); 338 | System.out.println("First, incorrect results: "); 339 | System.out.println(heads); 340 | pause(); 341 | 342 | System.out.println("This time, fixed with ':with': "); 343 | heads = Peer.query("[:find (sum ?heads) . " + 344 | " :with ?monster " + 345 | " :in [[?monster ?heads]]]", 346 | Util.list(Util.list("Cerberus", 3), 347 | Util.list("Cyclops", 1), 348 | Util.list("Medusa", 1), 349 | Util.list("Chimera", 1))); 350 | System.out.println(heads); 351 | pause(); 352 | 353 | // Aggregate examples 354 | System.out.println("Using 'max' and 'min' aggregates to get shortest and longest durations."); 355 | results = Peer.query("[:find [(min ?dur) (max ?dur)] " + 356 | " :where [_ :track/duration ?dur]]", 357 | db); 358 | System.out.println(results); 359 | pause(); 360 | 361 | System.out.println("Sum of all track counts."); 362 | Long sum = Peer.query("[:find (sum ?count) . " + 363 | " :with ?medium " + 364 | " :where [?medium :medium/trackCount ?count]]", 365 | db); 366 | System.out.println(sum); 367 | pause(); 368 | 369 | System.out.println("Counting with and without count-distinct: "); 370 | results = Peer.query("[:find [(count ?name) (count-distinct ?name)] " + 371 | " :with ?artist " + 372 | " :where [?artist :artist/name ?name]]", 373 | db); 374 | System.out.println(results); 375 | pause(); 376 | 377 | System.out.println("Count of tracks."); 378 | results = Peer.query("[:find (count ?track) " + 379 | " :where [?track :track/name]]", 380 | db); 381 | System.out.println(results); 382 | pause(); 383 | 384 | System.out.println("Some basic stats..."); 385 | results = Peer.query("[:find ?year (median ?namelen) (avg ?namelen) (stddev ?namelen) " + 386 | " :with ?track " + 387 | " :where [?track :track/name ?name] " + 388 | " [(count ?name) ?namelen] " + 389 | " [?medium :medium/tracks ?track] " + 390 | " [?release :release/media ?medium] " + 391 | " [?release :release/year ?year]]", 392 | db); 393 | System.out.println(results); 394 | pause(); 395 | 396 | 397 | System.out.println("Set of distinct values..."); 398 | results = Peer.query("[:find (distinct ?v) . " + 399 | " :in [?v ...]] ", 400 | Util.list(1, 1, 2, 2, 2, 3)); 401 | System.out.println(results); 402 | pause(); 403 | 404 | System.out.println("Five shortest and five longest track durations in milliseconds."); 405 | results = Peer.query("[:find [(min 5 ?millis) (max 5 ?millis)] " + 406 | " :where [?track :track/duration ?millis]]", 407 | db); 408 | System.out.println(results); 409 | pause(); 410 | 411 | System.out.println("Two random names using rand (duplicates tolerated) and sample (only distinct)"); 412 | results = Peer.query("[:find [(rand 2 ?name) (sample 2 ?name)] " + 413 | " :where [_ :artist/name ?name]]", 414 | db); 415 | System.out.println(results); 416 | pause(); 417 | 418 | System.out.println("Using a QueryRequest to return a relation"); 419 | QueryRequest queryRequest = QueryRequest.create("[:find ?artist-name ?release-name " + 420 | " :in $ ?artist-name " + 421 | " :where [?artist :artist/name ?artist-name] " + 422 | " [?release :release/artists ?artist] " + 423 | " [?release :release/name ?release-name]]", 424 | db, "John Lennon"); 425 | Collection> queryResultRelation = Peer.query(queryRequest); 426 | 427 | System.out.println(queryResultRelation); 428 | pause(); 429 | 430 | System.out.println("Using a QueryRequest to return a collection"); 431 | queryRequest = QueryRequest.create("[:find [?release-name ...]" + 432 | " :in $ ?artist-name " + 433 | " :where [?artist :artist/name ?artist-name] " + 434 | " [?release :release/artists ?artist] " + 435 | " [?release :release/name ?release-name]]", 436 | db, "John Lennon"); 437 | Collection queryResultCollection = Peer.query(queryRequest); 438 | 439 | System.out.println(queryResultCollection); 440 | pause(); 441 | 442 | System.out.println("Using a QueryRequest to return a single tuple"); 443 | queryRequest = QueryRequest.create("[:find [?year ?month ?day]" + 444 | " :in $ ?name" + 445 | " :where [?artist :artist/name ?name] " + 446 | " [?artist :artist/startDay ?day] " + 447 | " [?artist :artist/startMonth ?month] " + 448 | " [?artist :artist/startYear ?year]]", 449 | db, "John Lennon"); 450 | List queryResultSingleTuple = Peer.query(queryRequest); 451 | 452 | System.out.println(queryResultSingleTuple); 453 | pause(); 454 | 455 | 456 | System.out.println("Using a QueryRequest to return a single scalar"); 457 | queryRequest = QueryRequest.create("[:find ?year . " + 458 | " :in $ ?name " + 459 | " :where [?artist :artist/name ?name] " + 460 | " [?artist :artist/startYear ?year]]", 461 | db, "John Lennon"); 462 | Long queryResultSingleScalar = Peer.query(queryRequest); 463 | 464 | System.out.println(queryResultSingleScalar); 465 | pause(); 466 | 467 | 468 | System.out.println("Timeout a long running query."); 469 | queryRequest = QueryRequest.create("[:find ?track-name " + 470 | " :in $ ?artist-name " + 471 | " :where [?track :track/artists ?artist] " + 472 | " [?track :track/name ?track-name] " + 473 | " [?artist :artist/name ?artist-name]]", 474 | db, "John Lennon").timeout(100); 475 | 476 | Exception error = null; 477 | try { 478 | Peer.query(queryRequest); 479 | } catch (Exception e) { 480 | error = e; 481 | if (error.getMessage().contains("Query canceled")) { 482 | System.out.println("Caught expected timeout exception: " + error.getMessage()); 483 | } else { 484 | throw new RuntimeException(e); 485 | } 486 | } 487 | if (error == null) { 488 | System.out.println("Expected query to timeout."); 489 | } 490 | } 491 | 492 | private static final Scanner scanner = new Scanner(System.in); 493 | 494 | private static void pause() { 495 | if (System.getProperty("NOPAUSE") == null) { 496 | System.out.println("\nPress enter to continue..."); 497 | scanner.nextLine(); 498 | 499 | } 500 | } 501 | } 502 | 503 | -------------------------------------------------------------------------------- /src/java/datomic/samples/QueryAsData.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | import datomic.Peer; 6 | 7 | import java.io.IOException; 8 | import java.io.InputStreamReader; 9 | import java.io.Reader; 10 | import java.net.URI; 11 | import java.net.URL; 12 | import java.util.List; 13 | 14 | import static datomic.Peer.q; 15 | import static datomic.Util.*; 16 | import static datomic.samples.IO.*; 17 | import static datomic.samples.Fns.scratchConnection; 18 | 19 | public class QueryAsData { 20 | public static Object tempid() { 21 | return Peer.tempid(":db.part/user"); 22 | } 23 | public static void main(String[] args) throws IOException { 24 | Connection conn = scratchConnection(); 25 | 26 | URL url = resource("datomic-java-examples/social-news.edn"); 27 | 28 | transactAll(conn, new InputStreamReader(url.openStream())); 29 | 30 | // tx data is plain lists and maps 31 | conn.transact( 32 | list(map(":db/id", tempid(), ":user/firstName", "Stewart", ":user/lastName", "Brand"), 33 | map(":db/id", tempid(), ":user/firstName", "Stuart", ":user/lastName", "Smalley"), 34 | map(":db/id", tempid(), ":user/firstName", "John", ":user/lastName", "Stewart"))); 35 | 36 | Database db = conn.db(); 37 | 38 | // Find all Stewart first names (should return 1 tuple) 39 | System.out.println(q("[:find ?e :in $ ?name :where [?e :user/firstName ?name]]", db, "Stewart")); 40 | 41 | // Find all Stewart or Stuart first names (should return 2 tuples) 42 | List names = list("Stewart", "Stuart"); 43 | System.out.println(q("[:find ?e :in $ [?name ...] :where [?e :user/firstName ?name]]", db, names)); 44 | 45 | // Find all [Stewart|Stuart] [first|last] names (should return 3 tuples) 46 | List nameAttributes = list(read(":user/firstName"), read(":user/lastName")); 47 | System.out.println(q("[:find ?e :in $ [?name ...] [?attr ...] :where [?e ?attr ?name]]", db, names, nameAttributes)); 48 | 49 | // Build a query out of data. You might need this if e.g. writing a query optimizer. 50 | // Do *not* do this if parameterizing inputs (as shown above) is sufficient! 51 | List firstNameQuery = list(read(":find"), read("?e"), 52 | read(":in"), read("$"), read("?name"), 53 | read(":where"), list(read("?e"), read(":user/firstName"), read("?name"))); 54 | 55 | // Find all Stewart first names (should return 1 tuple) 56 | System.out.println(q(firstNameQuery, db, "Stewart")); 57 | } 58 | } 59 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Schema.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Database; 4 | 5 | import static datomic.Peer.query; 6 | import static datomic.Util.read; 7 | 8 | public class Schema { 9 | public static final Object CARDINALITY_ONE = read(":db.cardinality/one"); 10 | public static final Object CARDINALITY_MANY = read(":db.cardinality/many"); 11 | 12 | public static Object cardinality(Object db, Object attr) { 13 | return query("[:find ?v . " + 14 | ":in $ ?attr " + 15 | ":where " + 16 | "[?attr :db/cardinality ?card] " + 17 | "[?card :db/ident ?v]]", db, attr); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/java/datomic/samples/Trust.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | import datomic.Datom; 6 | 7 | import java.io.IOException; 8 | import java.io.InputStreamReader; 9 | import java.net.URL; 10 | import java.util.concurrent.ExecutionException; 11 | 12 | import static datomic.Peer.query; 13 | import static datomic.Peer.tempid; 14 | import static datomic.Util.list; 15 | import static datomic.Util.map; 16 | import static datomic.samples.Fns.scratchConnection; 17 | import static datomic.samples.IO.resource; 18 | import static datomic.samples.IO.transactAll; 19 | import static datomic.samples.PrettyPrint.print; 20 | 21 | public class Trust { 22 | public static void main(String[] args) throws IOException, ExecutionException, InterruptedException { 23 | Connection conn = scratchConnection(); 24 | URL url = resource("datomic-java-examples/social-news.edn"); 25 | transactAll(conn, new InputStreamReader(url.openStream())); 26 | 27 | conn.transact(list(map(":db/id", tempid(":db.part/user"), 28 | ":story/title", "ElastiCache in 6 minutes", 29 | ":story/url", "http://blog.datomic.com/2012/09/elasticache-in-5-minutes.html"), 30 | map(":db/id", tempid(":db.part/tx"), 31 | ":source/confidence", 95L))).get(); 32 | 33 | conn.transact(list(map(":db/id", tempid(":db.part/user"), 34 | ":story/title", "Request for Urgent Business Relationship", 35 | ":story/url", "http://example.com/bogus-url"), 36 | map(":db/id", tempid(":db.part/tx"), 37 | ":source/confidence", 40L))).get(); 38 | 39 | Database db = conn.db(); 40 | 41 | System.out.println("\nAll stories..."); 42 | print(allStories(db)); 43 | 44 | System.out.println("\nStories with 90% confidence, by query..."); 45 | print(storiesWithHighConfidenceByQuery(db)); 46 | 47 | System.out.println("\nStories with 90% confidence, by filter..."); 48 | print(storiesWithHighConfidenceByFilter(db)); 49 | } 50 | 51 | public static Object allStories(Database db) { 52 | return query("[:find [?title ...]" + 53 | " :where [_ :story/title ?title]]", db); 54 | } 55 | 56 | public static Object storiesWithHighConfidenceByQuery(Database db) { 57 | return query("[:find [?title ...]" + 58 | " :where [_ :story/title ?title ?tx]" + 59 | " [?tx :source/confidence ?conf]" + 60 | " [(<= 90 ?conf)]]", db); 61 | } 62 | 63 | /** 64 | * Returns database filtered to only facts whose transactions have 65 | * :source/confidence level of 90% or higher 66 | */ 67 | public static Database filterByConfidence(Database db, final long conf) { 68 | return db.filter(new Database.Predicate() { 69 | public boolean apply(Database db, Datom datom) { 70 | Long confidence = (Long) db.entity(datom.tx()).get(":source/confidence"); 71 | return (confidence != null) && (confidence > conf); 72 | } 73 | }); 74 | } 75 | 76 | public static Object storiesWithHighConfidenceByFilter(Database db) { 77 | return query("[:find [?title ...]" + 78 | " :where [_ :story/title ?title]]", filterByConfidence(db, 90L)); 79 | } 80 | 81 | } 82 | 83 | -------------------------------------------------------------------------------- /src/java/datomic/samples/TxFunctions.java: -------------------------------------------------------------------------------- 1 | package datomic.samples; 2 | 3 | import datomic.Connection; 4 | import datomic.Database; 5 | 6 | import java.io.IOException; 7 | import java.util.concurrent.Future; 8 | import java.util.concurrent.ExecutionException; 9 | import java.lang.IllegalStateException; 10 | import java.util.List; 11 | import java.util.Map; 12 | 13 | import static datomic.Peer.query; 14 | import static datomic.Peer.tempid; 15 | import static datomic.Peer.toT; 16 | import static datomic.Peer.function; 17 | import static datomic.Util.list; 18 | import static datomic.samples.Fns.scratchConnection; 19 | import static datomic.Util.map; 20 | import static datomic.Util.read; 21 | 22 | public class TxFunctions { 23 | 24 | /* 25 | * Function intended for use as a Datomic transaction function. ensureComposite will fail to transact if the 26 | * existing two key/value combinations specified in parameters are already set for an entity in the database. 27 | * 28 | * The resulting exception will report the entity and the tx value. 29 | * 30 | * @param db a database value 31 | * @param k1 first key of composite uniqueness constraint 32 | * @param v1 value corresponding to first key 33 | * @param k2 second key 34 | * @param v2 second value 35 | * @return transaction data to create entity with attr/value pairs k1:v1, k2:v2. 36 | */ 37 | public static List ensureComposite(Database db, Object k1, Object v1, Object k2, Object v2) { 38 | String compositeQuery = "[:find [?e ?t1 ?t2] " + 39 | ":in $ ?k1 ?v1 ?k2 ?v2 " + 40 | ":where " + 41 | "[?e ?k1 ?v1 ?t1] " + 42 | "[?e ?k2 ?v2 ?t2]]"; 43 | List