[−][src]Crate neo4rs
Neo4j driver compatible with neo4j 4.x versions
- An implementation of the bolt protocol to interact with Neo4j server
- async/await apis using tokio
- Supports bolt 4.2 specification
- tested with Neo4j versions: 4.0, 4.1, 4.2
Examples
use neo4rs::*; use std::sync::Arc; use std::sync::atomic::{AtomicU32, Ordering}; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let id = Uuid::new_v4().to_string(); let graph = Arc::new(Graph::new(&uri, user, pass).await.unwrap()); let mut result = graph.run( query("CREATE (p:Person {id: $id})").param("id", id.clone()) ).await.unwrap(); let mut handles = Vec::new(); let mut count = Arc::new(AtomicU32::new(0)); for _ in 1..=42 { let graph = graph.clone(); let id = id.clone(); let count = count.clone(); let handle = tokio::spawn(async move { let mut result = graph.execute( query("MATCH (p:Person {id: $id}) RETURN p").param("id", id) ).await.unwrap(); while let Ok(Some(row)) = result.next().await { count.fetch_add(1, Ordering::Relaxed); } }); handles.push(handle); } futures::future::join_all(handles).await; assert_eq!(count.load(Ordering::Relaxed), 42); }
Configurations
Use the config builder to override the default configurations like
fetch_size
- number of rows to fetch in batches (default is 200)max_connections
- maximum size of the connection pool (default is 16)db
- the database to connect to (default isneo4j
)
use neo4rs::*; use futures::stream::*; #[tokio::main] async fn main() { let config = config() .uri("127.0.0.1:7687") .user("neo4j") .password("neo") .db("neo4j") .fetch_size(500) .max_connections(10) .build() .unwrap(); let graph = Graph::connect(config).await.unwrap(); let mut result = graph.execute(query("RETURN 1")).await.unwrap(); let row = result.next().await.unwrap().unwrap(); let value: i64 = row.get("1").unwrap(); assert_eq!(1, value); assert!(result.next().await.unwrap().is_none()); }
Nodes
A simple example to create a node and consume the created node from the row stream.
Graph::run
just returnserrors::Result
<()>
, usually used for write only queries.Graph::execute
returnserrors::Result
<
RowStream
>
use neo4rs::*; use futures::stream::*; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); assert!(graph.run(query("RETURN 1")).await.is_ok()); let mut result = graph.execute( query( "CREATE (friend:Person {name: $name}) RETURN friend") .param("name", "Mr Mark") ).await.unwrap(); while let Ok(Some(row)) = result.next().await { let node: Node = row.get("friend").unwrap(); let id = node.id(); let labels = node.labels(); let name: String = node.get("name").unwrap(); assert_eq!(name, "Mr Mark"); assert_eq!(labels, vec!["Person"]); assert!(id > 0); } }
Transactions
Start a new transaction using Graph::start_txn
, which will return a handle Txn
that can
be used to Txn::commit
or Txn::rollback
the transaction.
Note that the handle takes a connection from the connection pool, which will be released once the Txn is dropped
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let txn = graph.start_txn().await.unwrap(); let id = Uuid::new_v4().to_string(); let result = txn.run_queries(vec![ query("CREATE (p:Person {id: $id})").param("id", id.clone()), query("CREATE (p:Person {id: $id})").param("id", id.clone()) ]).await; assert!(result.is_ok()); txn.commit().await.unwrap(); let mut result = graph .execute(query("MATCH (p:Person) WHERE p.id = $id RETURN p.id").param("id", id.clone())) .await .unwrap(); }
Streams within a transaction
Each RowStream
returned by various execute within the same transaction are well isolated,
so you can consume the stream anytime within the transaction using RowStream::next
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let config = config() .uri("127.0.0.1:7687") .user("neo4j") .password("neo") .fetch_size(1) .build() .unwrap(); let graph = Graph::connect(config).await.unwrap(); let name = Uuid::new_v4().to_string(); let txn = graph.start_txn().await.unwrap(); txn.run_queries(vec![ query("CREATE (p { name: $name })").param("name", name.clone()), query("CREATE (p { name: $name })").param("name", name.clone()), ]) .await .unwrap(); //start stream_one let mut stream_one = txn .execute(query("MATCH (p {name: $name}) RETURN p").param("name", name.clone())) .await .unwrap(); let row = stream_one.next().await.unwrap().unwrap(); assert_eq!(row.get::<Node>("p").unwrap().get::<String>("name").unwrap(), name.clone()); //start stream_two let mut stream_two = txn.execute(query("RETURN 1")).await.unwrap(); let row = stream_two.next().await.unwrap().unwrap(); assert_eq!(row.get::<i64>("1").unwrap(), 1); //stream_one is still active here let row = stream_one.next().await.unwrap().unwrap(); assert_eq!(row.get::<Node>("p").unwrap().get::<String>("name").unwrap(), name.clone()); //stream_one completes assert!(stream_one.next().await.unwrap().is_none()); //stream_two completes assert!(stream_two.next().await.unwrap().is_none()); txn.commit().await.unwrap(); }
Rollback a transaction
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let txn = graph.start_txn().await.unwrap(); let id = Uuid::new_v4().to_string(); // create a node txn.run(query("CREATE (p:Person {id: $id})").param("id", id.clone())) .await .unwrap(); // rollback the changes txn.rollback().await.unwrap(); // changes not updated in the database let mut result = graph .execute(query("MATCH (p:Person) WHERE p.id = $id RETURN p.id").param("id", id.clone())) .await .unwrap(); assert!(result.next().await.unwrap().is_none()); }
Txn vs Graph
Everytime you execute a query using Graph::run
or Graph::execute
, a new connection is
taken from the pool and released immediately.
However, when you execute a query on a transaction using Txn::run
or Txn::execute
the
same connection will be reused, the underlying connection will be released to the pool in a
clean state only after you commit/rollback the transaction and the Txn
handle is dropped.
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let txn = graph.start_txn().await.unwrap(); let id = Uuid::new_v4().to_string(); txn.run(query("CREATE (p:Person {id: $id})").param("id", id.clone())) .await .unwrap(); txn.run(query("CREATE (p:Person {id: $id})").param("id", id.clone())) .await .unwrap(); // graph.execute(..) will not see the changes done above as the txn is not committed yet let mut result = graph .execute(query("MATCH (p:Person) WHERE p.id = $id RETURN p.id").param("id", id.clone())) .await .unwrap(); assert!(result.next().await.unwrap().is_none()); txn.commit().await.unwrap(); //changes are now seen as the transaction is committed. let mut result = graph .execute(query("MATCH (p:Person) WHERE p.id = $id RETURN p.id").param("id", id.clone())) .await .unwrap(); assert!(result.next().await.unwrap().is_some()); assert!(result.next().await.unwrap().is_some()); assert!(result.next().await.unwrap().is_none()); }
Relationships
Bounded Relationship between nodes are created using cypher queries and the same can be parsed
from the RowStream
use neo4rs::*; use futures::stream::*; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let mut result = graph.execute( query("CREATE (p:Person { name: 'Oliver Stone' })-[r:WORKS_AT {as: 'Engineer'}]->(neo) RETURN r") ).await.unwrap(); let row = result.next().await.unwrap().unwrap(); let relation: Relation = row.get("r").unwrap(); assert!(relation.id() > -1); assert!(relation.start_node_id() > -1); assert!(relation.end_node_id() > -1); assert_eq!(relation.typ(), "WORKS_AT"); assert_eq!(relation.get::<String>("as").unwrap(), "Engineer"); }
Similar to bounded relation, an unbounded relation can also be created/parsed.
use neo4rs::*; use futures::stream::*; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let mut result = graph.execute( query("MERGE (p1:Person { name: 'Oliver Stone' })-[r:RELATED {as: 'friend'}]-(p2: Person {name: 'Mark'}) RETURN r") ).await.unwrap(); let row = result.next().await.unwrap().unwrap(); let relation: Relation = row.get("r").unwrap(); assert!(relation.id() > -1); assert!(relation.start_node_id() > -1); assert!(relation.end_node_id() > -1); assert_eq!(relation.typ(), "RELATED"); assert_eq!(relation.get::<String>("as").unwrap(), "friend"); }
Points
A 2d or 3d point can be represented with the types Point2D
and Point3D
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let mut result = graph .execute(query( "WITH point({ x: 2.3, y: 4.5, crs: 'cartesian' }) AS p1, point({ x: 1.1, y: 5.4, crs: 'cartesian' }) AS p2 RETURN distance(p1,p2) AS dist, p1, p2", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let dist: f64 = row.get("dist").unwrap(); let p1: Point2D = row.get("p1").unwrap(); let p2: Point2D = row.get("p2").unwrap(); assert_eq!(1.5, dist); assert_eq!(p1.sr_id(), 7203); assert_eq!(p1.x(), 2.3); assert_eq!(p1.y(), 4.5); assert_eq!(p2.sr_id(), 7203); assert_eq!(p2.x(), 1.1); assert_eq!(p2.y(), 5.4); assert!(result.next().await.unwrap().is_none()); let mut result = graph .execute(query( "RETURN point({ longitude: 56.7, latitude: 12.78, height: 8 }) AS point", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let point: Point3D = row.get("point").unwrap(); assert_eq!(point.sr_id(), 4979); assert_eq!(point.x(), 56.7); assert_eq!(point.y(), 12.78); assert_eq!(point.z(), 8.0); assert!(result.next().await.unwrap().is_none()); }
Raw bytes
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let mut result = graph .execute(query("RETURN $b as output").param("b", vec![11, 12])) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let b: Vec<u8> = row.get("output").unwrap(); assert_eq!(b, &[11, 12]); assert!(result.next().await.unwrap().is_none()); }
Durations
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let duration = std::time::Duration::new(5259600, 7); let mut result = graph .execute(query("RETURN $d as output").param("d", duration)) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let d: std::time::Duration = row.get("output").unwrap(); assert_eq!(d.as_secs(), 5259600); assert_eq!(d.subsec_nanos(), 7); assert!(result.next().await.unwrap().is_none()); }
Date
See NaiveDate for date abstraction, it captures the date without time component.
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let date = chrono::NaiveDate::from_ymd(1985, 2, 5); let mut result = graph .execute(query("RETURN $d as output").param("d", date)) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let d: chrono::NaiveDate = row.get("output").unwrap(); assert_eq!(d.to_string(), "1985-02-05"); assert!(result.next().await.unwrap().is_none()); }
Time
- NaiveTime captures only the time of the day
tuple
(NaiveTime,Option
<FixedOffset>) captures the time of the day along with the offset
Time as param
Pass a time as a parameter to the query:
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); //send time without offset as param let time = chrono::NaiveTime::from_hms_nano(11, 15, 30, 200); let mut result = graph.execute(query("RETURN $d as output").param("d", time)).await.unwrap(); let row = result.next().await.unwrap().unwrap(); let t: (chrono::NaiveTime, Option<chrono::FixedOffset>) = row.get("output").unwrap(); assert_eq!(t.0.to_string(), "11:15:30.000000200"); assert_eq!(t.1, None); assert!(result.next().await.unwrap().is_none()); //send time with offset as param let time = chrono::NaiveTime::from_hms_nano(11, 15, 30, 200); let offset = chrono::FixedOffset::east(3 * 3600); let mut result = graph .execute(query("RETURN $d as output").param("d", (time, offset))) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: (chrono::NaiveTime, Option<chrono::FixedOffset>) = row.get("output").unwrap(); assert_eq!(t.0.to_string(), "11:15:30.000000200"); assert_eq!(t.1, Some(offset)); assert!(result.next().await.unwrap().is_none()); }
Parsing time from result
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); //Parse time without offset let mut result = graph .execute(query( " WITH time({hour:10, minute:15, second:30, nanosecond: 200}) AS t RETURN t", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: (chrono::NaiveTime, Option<chrono::FixedOffset>) = row.get("t").unwrap(); assert_eq!(t.0.to_string(), "10:15:30.000000200"); assert_eq!(t.1, None); assert!(result.next().await.unwrap().is_none()); //Parse time with timezone information let mut result = graph .execute(query( " WITH time({hour:10, minute:15, second:33, nanosecond: 200, timezone: '+01:00'}) AS t RETURN t", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: (chrono::NaiveTime, Option<chrono::FixedOffset>) = row.get("t").unwrap(); assert_eq!(t.0.to_string(), "10:15:33.000000200"); assert_eq!(t.1, Some(chrono::FixedOffset::east(1 * 3600))); assert!(result.next().await.unwrap().is_none()); }
DateTime
- DateTime captures the date and time with offset
- NaiveDateTime captures the date time without offset
tuple
(NaiveDateTime, String) captures the date/time and the time zone id
DateTime as param
Pass a DateTime as parameter to the query:
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); //send datetime as parameter in the query let datetime = chrono::DateTime::parse_from_rfc2822("Tue, 01 Jul 2003 10:52:37 +0200").unwrap(); let mut result = graph .execute(query("RETURN $d as output").param("d", datetime)) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: chrono::DateTime<chrono::FixedOffset> = row.get("output").unwrap(); assert_eq!(t.to_string(), "2003-07-01 10:52:37 +02:00"); assert!(result.next().await.unwrap().is_none()); //send NaiveDateTime as parameter in the query let localdatetime = chrono::NaiveDateTime::parse_from_str("2015-07-01 08:55:59.123", "%Y-%m-%d %H:%M:%S%.f").unwrap(); let mut result = graph .execute(query("RETURN $d as output").param("d", localdatetime)) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: chrono::NaiveDateTime = row.get("output").unwrap(); assert_eq!(t.to_string(), "2015-07-01 08:55:59.123"); assert!(result.next().await.unwrap().is_none()); //send NaiveDateTime with timezone id as parameter in the query let datetime = chrono::NaiveDateTime::parse_from_str("2015-07-03 08:55:59.555", "%Y-%m-%d %H:%M:%S%.f").unwrap(); let timezone = "Europe/Paris"; let mut result = graph .execute(query("RETURN $d as output").param("d", (datetime, timezone))) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let (time, zone): (chrono::NaiveDateTime, String) = row.get("output").unwrap(); assert_eq!(time.to_string(), "2015-07-03 08:55:59.555"); assert_eq!(zone, "Europe/Paris"); assert!(result.next().await.unwrap().is_none()); }
Parsing DateTime from result
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); //Parse NaiveDateTime from result let mut result = graph .execute(query( "WITH localdatetime('2015-06-24T12:50:35.556') AS t RETURN t", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: chrono::NaiveDateTime = row.get("t").unwrap(); assert_eq!(t.to_string(), "2015-06-24 12:50:35.556"); assert!(result.next().await.unwrap().is_none()); //Parse DateTime from result let mut result = graph .execute(query( "WITH datetime('2015-06-24T12:50:35.777+0100') AS t RETURN t", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let t: chrono::DateTime<chrono::FixedOffset> = row.get("t").unwrap(); assert_eq!(t.to_string(), "2015-06-24 12:50:35.777 +01:00"); assert!(result.next().await.unwrap().is_none()); //Parse NaiveDateTime with zone id from result let mut result = graph .execute(query( "WITH datetime({ year:1984, month:11, day:11, hour:12, minute:31, second:14, nanosecond: 645876123, timezone:'Europe/Stockholm' }) AS d return d", )) .await .unwrap(); let row = result.next().await.unwrap().unwrap(); let (datetime, zone_id): (chrono::NaiveDateTime, String) = row.get("d").unwrap(); assert_eq!(datetime.to_string(), "1984-11-11 12:31:14.645876123"); assert_eq!(zone_id, "Europe/Stockholm"); assert!(result.next().await.unwrap().is_none()); }
Path
use neo4rs::*; use futures::stream::*; use uuid::Uuid; #[tokio::main] async fn main() { let uri = "127.0.0.1:7687"; let user = "neo4j"; let pass = "neo"; let graph = Graph::new(uri, user, pass).await.unwrap(); let name = Uuid::new_v4().to_string(); graph.run( query("CREATE (p:Person { name: $name })-[r:WORKS_AT]->(n:Company { name: 'Neo'})").param("name", name.clone()), ).await.unwrap(); let mut result = graph.execute( query("MATCH p = (person:Person { name: $name })-[r:WORKS_AT]->(c:Company) RETURN p").param("name", name), ).await.unwrap(); let row = result.next().await.unwrap().unwrap(); let path: Path = row.get("p").unwrap(); assert_eq!(path.ids().len(), 2); assert_eq!(path.nodes().len(), 2); assert_eq!(path.rels().len(), 1); assert!(result.next().await.unwrap().is_none()); }
Structs
Config | The configuration used to connect to the database, see [ |
ConfigBuilder | A builder to override default configurations and build the |
Graph | A neo4j database abstraction |
Node | Snapshot of a node within a graph database |
Path | Alternating sequence of nodes and relationships |
Point2D | Represents a single location in 2-dimensional space |
Point3D | Represents a single location in 3-dimensional space |
Query | Abstracts a cypher query that is sent to neo4j server. |
Relation | Snapshot of a relationship within a graph database |
Row | Represents a row returned as a result of executing a query. |
RowStream | An abstraction over a stream of rows, this is returned as a result of [ |
Txn | A handle which is used to control a transaction, created as a result of [ |
UnboundedRelation | Relationship detail without start or end node information |
Enums
Error | |
Version |
Functions
config | Creates a config builder with reasonable default values wherever appropriate. |
query | Returns a |
unexpected |
Type Definitions
Result |