驱动程序配置

这是 GraphQL 库版本 6 的文档。有关长期支持 (LTS) 版本 5，请参阅 GraphQL 库版本 5 LTS.

此页面描述了 Neo4j GraphQL 库驱动程序的配置。

Neo4j 驱动程序

为了使 Neo4j GraphQL 库正常工作，必须在您的 Neo4jGraphQL 实例构造时传入 Neo4j JavaScript 驱动程序 的实例，或者在每个请求的 context.executionContext 中传入驱动程序、会话或事务。

此页面中的示例假定 Neo4j 数据库运行在“bolt://localhost:7687”上，用户名为“username”，密码为“password”。

Neo4j GraphQL 库

驱动程序在 Neo4jGraphQL 构造函数中

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";
import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });

const server = new ApolloServer({
    schema: await neoSchema.getSchema(),
});

await startStandaloneServer(server, {
    context: async ({ req }) => ({ req }),
});

驱动程序在上下文中

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";
import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });

const server = new ApolloServer({
    schema: await neoSchema.getSchema(),
});

await startStandaloneServer(server, {
    context: async ({ req }) => ({ req, executionContext: driver }),
});

会话在上下文中

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";
import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);
const session = driver.session();

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });

const server = new ApolloServer({
    schema: await neoSchema.getSchema(),
});

await startStandaloneServer(server, {
    context: async ({ req }) => ({ req, executionContext: session }),
});

事务在上下文中

import { ApolloServer } from "@apollo/server";
import { startStandaloneServer } from "@apollo/server/standalone";
import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);
const session = driver.transaction();
const transaction = session.beginTransaction();

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });

const server = new ApolloServer({
    schema: await neoSchema.getSchema(),
});

await startStandaloneServer(server, {
    context: async ({ req }) => ({ req, executionContext: transaction }),
});

数据库兼容性

使用 Neo4jGraphQL 实例上可用的 checkNeo4jCompat 方法确保指定的 DBMS 具有所需版本，并且具有必要的可用函数和过程。如果 DBMS 不兼容，checkNeo4jCompat 将抛出 Error，并包含有关不兼容性的详细信息。

Neo4jGraphQL

import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });
await neoSchema.checkNeo4jCompat();

指定 Neo4j 数据库

通过所有解析器共享的 context 中的 sessionConfig 下的 database 字段，指定要在 DBMS 内使用的数据库。

import { ApolloServer } from '@apollo/server';
import { startStandaloneServer } from '@apollo/server/standalone';
import { Neo4jGraphQL } from "@neo4j/graphql";
import neo4j from "neo4j-driver";

const typeDefs = `#graphql
    type User @node {
        name: String
    }
`;

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("username", "password")
);

const neoSchema = new Neo4jGraphQL({ typeDefs, driver });

const server = new ApolloServer({
    schema: await neoSchema.getSchema(),
});

await startStandaloneServer(server, {
    context: async ({ req }) => ({ req, sessionConfig: { database: "my-database" }}),
});