Add support for multidatabase

Use the value of context.neo4jDatabase as the database name

Author: johnymontana

example/apollo-server/multidatabase.js

@@ -0,0 +1,71 @@
+import { makeAugmentedSchema } from '../../src/index';
+import { ApolloServer } from 'apollo-server';
+import neo4j from 'neo4j-driver';
+
+const typeDefs = `
+
+type User {
+    name: String!
+    wrote: [Review] @relation(name: "WROTE", direction: "OUT")
+  }
+  type Review {
+    date: Date!
+    reviewId: String!
+    stars: Float!
+    text: String
+    reviews: [Business] @relation(name: "REVIEWS", direction: "OUT")
+    users: [User] @relation(name: "WROTE", direction: "IN")
+  }
+  type Category {
+    name: String!
+    business: [Business] @relation(name: "IN_CATEGORY", direction: "IN")
+  }
+  type Business {
+    address: String!
+    city: String!
+    location: Point!
+    name: String!
+    state: String!
+    in_category: [Category] @relation(name: "IN_CATEGORY", direction: "OUT")
+    reviews: [Review] @relation(name: "REVIEWS", direction: "IN")
+  }
+`;
+
+const schema = makeAugmentedSchema({ typeDefs });
+
+const driver = neo4j.driver(
+  'neo4j://localhost:7687',
+  neo4j.auth.basic('neo4j', 'letmein'),
+  { encrypted: false }
+);
+
+// Create two separate servers by hardcoding value for context.neo4jDatabase
+// const sanmateoServer = new ApolloServer({
+//   schema,
+//   context: { driver, neo4jDatabase: 'sanmateo' }
+// });
+
+// sanmateoServer.listen(3003, '0.0.0.0').then(({ url }) => {
+//   console.log(`San Mateo GraphQL API ready at ${url}`);
+// });
+
+// const missoulaServer = new ApolloServer({
+//   schema,
+//   context: { driver, neo4jDatabase: 'missoula' }
+// });
+
+// missoulaServer.listen(3004, '0.0.0.0').then(({ url }) => {
+//   console.log(`Missoula GraphQL API ready at ${url}`);
+// });
+
+// Or we can add a header to the request
+const server = new ApolloServer({
+  schema,
+  context: ({ req }) => {
+    return { driver, neo4jDatabase: req.headers['x-database'] };
+  }
+});
+
+server.listen(3003, '0.0.0.0').then(({ url }) => {
+  console.log(`GraphQL API ready at ${url}`);
+});

src/index.js

@@ -67,8 +67,26 @@ instead: \`DEBUG=neo4j-graphql-js\`.
 
   context.driver._userAgent = `neo4j-graphql-js/${neo4jGraphQLVersion}`;
 
-  // TODO: Is this a 4.0 driver instance? Check bolt path for default database name and use that when creating the session
-  const session = context.driver.session();
+  let session;
+
+  if (context.neo4jDatabase) {
+    // database is specified in context object
+    try {
+      // connect to the specified database
+      // must be using 4.x version of driver
+      session = context.driver.session({
+        database: context.neo4jDatabase
+      });
+    } catch (e) {
+      // error - not using a 4.x version of driver!
+      // fall back to default database
+      session = context.driver.session();
+    }
+  } else {
+    // no database specified
+    session = context.driver.session();
+  }
+
   let result;
 
   try {