Optimised Cypher queries in Neo4j example (#25973)

Thank you for including a Neo4j example! This PR rewrites the Cypher queries using a [pattern comprehension](https://neo4j.com/docs/cypher-manual/current/syntax/lists/#cypher-pattern-comprehension) which will make them more performant and removes the need for the `collect(DISTINCT ...)` step.
vercel · Jul 19, 2021 · 9774d9b · 9774d9b
1 parent 7fea8f3
commit 9774d9b
Show file tree

Hide file tree

Showing 8 changed files with 32 additions and 31 deletions.
diff --git a/examples/with-neo4j/package.json b/examples/with-neo4j/package.json
@@ -6,7 +6,7 @@
     "start": "next start"
   },
   "dependencies": {
-    "neo4j-driver": "4.1.1",
+    "neo4j-driver": "^4.3.1",
     "next": "latest",
     "react": "^17.0.2",
     "react-dom": "^17.0.2",

diff --git a/examples/with-neo4j/pages/actor/[name].js b/examples/with-neo4j/pages/actor/[name].js
@@ -29,7 +29,7 @@ export default function Actor() {
             <h2>Information</h2>
             <div>
               <strong>Born: </strong>
-              {data.actor.born.low}
+              {data.actor.born}
             </div>
           </div>
           <div className="movies">

diff --git a/examples/with-neo4j/pages/api/actors/[name].js b/examples/with-neo4j/pages/api/actors/[name].js
@@ -17,9 +17,9 @@ export default async function handler(req, res) {
           async (transaction) => {
             const cypher = `
               MATCH (actor:Person {name: $actorName})
-              MATCH (m:Movie)
-              WHERE (actor)-[:ACTED_IN]->(m)
-              RETURN actor {.*, movies: collect(m.title)} as actor
+              RETURN actor {.*,
+                movies: [ (actor)-[:ACTED_IN]->(m) | m.title ]
+              } as actor
             `
 
             const actorTxResponse = await transaction.run(cypher, { actorName })

diff --git a/examples/with-neo4j/pages/api/movies/[title].js b/examples/with-neo4j/pages/api/movies/[title].js
@@ -17,11 +17,10 @@ export default async function handler(req, res) {
           async (transaction) => {
             const cypher = `
               MATCH (movie:Movie {title: $movieTitle})
-              MATCH (actor:Person)
-              WHERE (movie)<-[:ACTED_IN]-(actor)
-              MATCH (director:Person)
-              WHERE (movie)<-[:DIRECTED]-(director)
-              RETURN movie {.*, actors: collect(DISTINCT actor.name), directed: collect(DISTINCT director.name)} as movie
+              RETURN movie {.*,
+                actors: [ (actor)-[:ACTED_IN]->(movie) | actor.name ],
+                directed: [ (director)-[:DIRECTED]->(movie) | director.name ]
+              } as movie
             `
 
             const movieTxResponse = await transaction.run(cypher, {

diff --git a/examples/with-neo4j/pages/api/movies/index.js b/examples/with-neo4j/pages/api/movies/index.js
@@ -13,11 +13,11 @@ export default async function handler(req, res) {
           async (transaction) => {
             const cypher = `
               MATCH (movie:Movie)
-              MATCH (actor:Person)
-              WHERE (movie)<-[:ACTED_IN]-(actor)
-              MATCH (director:Person)
-              WHERE (movie)<-[:DIRECTED]-(director)
-              RETURN movie {.*, actors: collect(DISTINCT actor.name), directed: collect(DISTINCT director.name)} as movie
+              RETURN movie {.*,
+                actors: [ (movie)<-[:ACTED_IN]-(actor) | actor.name ],
+                directed: [ (movie)<-[:DIRECTED]-(director) | director.name ]
+              } as movie
+              ORDER BY movie.title ASC
             `
 
             const moviesTxResponse = await transaction.run(cypher)

diff --git a/examples/with-neo4j/pages/index.js b/examples/with-neo4j/pages/index.js
@@ -42,16 +42,11 @@ export default function Home() {
                 <tr className="movie" key={movie.title}>
                   <th>{index + 1}</th>
                   <td>
-                    <Link
-                      href="/movie/[title]"
-                      as={{
-                        pathname: `/movie/${encodeURIComponent(movie.title)}`,
-                      }}
-                    >
+                    <Link href={`/movie/${encodeURIComponent(movie.title)}`}>
                       <a className="link">{movie.title}</a>
                     </Link>
                   </td>
-                  <td>{movie.released.low}</td>
+                  <td>{movie.released}</td>
                   <td>{movie.tagline}</td>
                   <td>
                     <ul>
@@ -64,12 +59,7 @@ export default function Home() {
                     <ul>
                       {movie.actors.map((actor) => (
                         <li key={actor}>
-                          <Link
-                            href="/actor/[name]"
-                            as={{
-                              pathname: `/actor/${encodeURIComponent(actor)}`,
-                            }}
-                          >
+                          <Link href={`/actor/${encodeURIComponent(actor)}`}>
                             <a className="link">{actor}</a>
                           </Link>
                         </li>

diff --git a/examples/with-neo4j/pages/movie/[title].js b/examples/with-neo4j/pages/movie/[title].js
@@ -33,13 +33,17 @@ export default function Movie() {
             </div>
             <div>
               <strong>Released: </strong>
-              {data.movie.released.low}
+              {data.movie.released}
             </div>
           </div>
           <div className="actors">
             <h2>Actors</h2>
             {data.movie.actors.map((actor) => (
-              <div key={actor}>{actor}</div>
+              <div key={actor}>
+                <Link key={actor} href={`/actor/${encodeURIComponent(actor)}`}>
+                  <a className="link">{actor}</a>
+                </Link>
+              </div>
             ))}
           </div>
           <div className="directors">
@@ -81,6 +85,9 @@ export default function Movie() {
           .movie {
             margin-bottom: 2rem;
           }
+          .movie a {
+            text-decoration: underline;
+          }
           .back {
             padding: 1rem 0;
           }

diff --git a/examples/with-neo4j/util/neo4j.js b/examples/with-neo4j/util/neo4j.js
@@ -11,7 +11,12 @@ const defaultOptions = {
 export default function getDriver() {
   const { uri, username, password } = defaultOptions
   if (!driver) {
-    driver = neo4j.driver(uri, neo4j.auth.basic(username, password))
+    // Note: There is a disparity between Neo4j (Java) Integers and JavaScript integers
+    // I have used `disableLosslessIntegers` to remove the need to call `.toNumber()` on each integer value
+    // For more info see: https://github.com/neo4j/neo4j-javascript-driver/#numbers-and-the-integer-type
+    driver = neo4j.driver(uri, neo4j.auth.basic(username, password), {
+      disableLosslessIntegers: true,
+    })
   }
 
   return driver