如何使用Graphql和Neo4j对类型字段添加唯一的约束？

Question

我正在制作一个GRANDStack应用程序，所以我使用neo4j和graphql，

在我的schema.graphql文件中有这样的类型：

type User {
  userId: ID!
  username: String! @unique
  mail: String! @unique
  password: String! @private
}

但是我仍然可以用相同的

当我在这里查看neo4j文档时，我知道这是可能的：https://neo4j.com/docs/graphql-manual/current/directives/#_unique

但目前我发现的唯一方法是在我的数据库中手动执行这样的操作：

CREATE CONSTRAINT ON (u:User) ASSERT u.mail IS UNIQUE;

但这不是个好主意，我希望这是自动的

我认为我的package.json也是最新的：

{
  "name": "grand-stack-starter-api",
  "version": "0.0.1",
  "description": "API app for GRANDstack",
  "main": "src/index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start:dev": "./node_modules/.bin/nodemon --watch src --ext js,graphql --exec babel-node  src/index.js",
    "build": "babel src --out-dir build && shx cp .env build 2>/dev/null || : && shx cp src/schema.graphql build",
    "now-build": "babel src --out-dir build && shx cp src/schema.graphql build",
    "start": "npm run build && node build/index.js",
    "seedDb": "./node_modules/.bin/babel-node src/seed/seed-db.js"
  },
  "author": "William Lyon",
  "license": "MIT",
  "dependencies": {
    "@apollo/client": "^3.2.5",
    "@neo4j/graphql": "^2.4.0",
    "apollo-server": "^3.5.0",
    "apollo-server-lambda": "^2.19.0",
    "csv-parse": "^4.10.1",
    "dotenv": "^7.0.0",
    "graphql": "^16.0.1",
    "neo4j-driver": "^4.4.0",
    "node-fetch": "^2.6.0",
    "react": "^16.13.1"
  },
  "devDependencies": {
    "@babel/cli": "^7.8.4",
    "@babel/core": "^7.9.0",
    "@babel/node": "^7.8.7",
    "@babel/plugin-proposal-class-properties": "^7.8.3",
    "@babel/plugin-transform-runtime": "^7.9.0",
    "@babel/preset-env": "^7.9.0",
    "@babel/preset-react": "^7.9.4",
    "@babel/preset-typescript": "^7.9.0",
    "@babel/runtime-corejs3": "^7.9.2",
    "babel-plugin-auto-import": "^1.0.5",
    "babel-plugin-module-resolver": "^4.0.0",
    "cross-env": "^7.0.2",
    "nodemon": "^1.19.1",
    "shx": "^0.3.2"
  }
}

Answer 1

因此，没有更新文档。

要解决这个问题，我首先必须遵循以下命令：https://neo4j.com/docs/graphql-manual/current/type-definitions/constraints/#type-definitions-constraints-unique

解决方案是添加这是错误的

await neoSchema.assertConstraints({ options: { create: true }});

我和在neo4j工作的人交谈过，他们的意见不一致，的右函数是：

await neoSchema.assertIndexesAndConstraints({ options: { create: true }});

如果像我一样，您不能等待，因为您的代码不在函数中，您可以使用.then执行如下操作：

 const neoSchema = new Neo4jGraphQL({
   ...
    })
 neoSchema
      .assertIndexesAndConstraints({ options: { create: true } })
      .then(() => {
        const server = new ApolloServer({
         ...

    app.listen({ host, port, path }, () => {
      console.log(`GraphQL server ready at http://${host}:${port}${path}`)
    })
  })