[英]Limit Depth on Recursive GraphQL Schema Query using graphql-sequelize resolver (Node.js, express-graphql)
I have 2 Models, User and Post.我有 2 个模型,用户和帖子。 I want to be able to get User information when querying a post, and be able to get all of a User's posts when querying a user.
我希望能够在查询帖子时获取用户信息,并在查询用户时获取用户的所有帖子。
they have an association as follows:他们有如下关联:
User.hasMany(Post, {
foreignKey: 'user',
as: 'posts'
});
Post.belongsTo(User, {
foreignKey: 'id',
sourceKey: 'user',
as: 'userObject'
})
Post.addScope('defaultScope', {
include: [{ model: User, as: 'userObject' }],
}, { override: true })
User.addScope('defaultScope', {
include: [{ model: Post, as: 'posts' }],
}, { override: true })
Here are my Models这是我的模型
User.js用户.js
module.exports.userType = new GQL.GraphQLObjectType({
name: 'User',
fields: () => {
const { postType } = require('../Post/Post');
return {
id: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'user unique id'
},
ci_username: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
unique: true,
description: 'case INSENSITIVE username of the user'
},
username: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'case SENSITIVE username of the user'
},
password: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'password for the user'
},
first_name: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'first name of user'
},
last_name: {
type: GQL.GraphQLString,
description: 'last name of user (optional)'
},
profile_picture: {
type: GQL.GraphQLString,
description: 'profile picture for the user'
},
posts: {
type: GQL.GraphQLList(postType),
description: 'list of users posts'
}
}
},
})
/** define User model for the database */
module.exports.User = db.define('user', {
id: {
type: Sequelize.UUID,
primaryKey: true,
unique: true,
},
ci_username: {
type: Sequelize.STRING,
unique: true,
},
username: Sequelize.STRING,
password: Sequelize.STRING,
first_name: Sequelize.STRING,
last_name: Sequelize.STRING,
profile_picture: Sequelize.STRING,
}, {
// Tells sequelize not to query the "CreatedAt" or "UpdatedAt" Columns
timestamps: false
})
Post.js Post.js
module.exports.postType = new GQL.GraphQLObjectType({
name: 'Post',
fields: () => {
const { userType } = require('../User/User');
return {
id: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'post unique id'
},
name: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'name of the post'
},
user: {
type: userType,
description: 'user object of who created the post'
},
created_at: {
type: new GQL.GraphQLNonNull(GQL.GraphQLString),
description: 'the datetime the post was created',
}
}
},
})
/** define User model for the database */
module.exports.Post = db.define('post', {
id: {
type: DataTypes.UUID,
primaryKey: true,
unique: true,
},
name: DataTypes.STRING,
user: {
type: DataTypes.STRING,
references: {
model: 'users',
key: 'id'
}
},
created_at: {
type: DataTypes.TIME,
defaultValue: DataTypes.NOW
}
}, {
// Tells sequelize not to query the "CreatedAt" or "UpdatedAt" Columns
timestamps: false
})
Here are my Queries:这是我的查询:
allUsers.js所有用户.js
const allUsers = {
type: new GQL.GraphQLList(userType),
args: {
username: {
description: 'username of the user',
type: GQL.GraphQLString,
},
// An arg with the key limit will automatically be converted to a limit on the target
limit: {
type: GQL.GraphQLInt,
default: 10
},
// An arg with the key order will automatically be converted to a order on the target
order: {
type: GQL.GraphQLString
}
},
// use graphql-sequelize resolver with the User model from database
resolve: resolver(User)
}
allPosts.js所有帖子.js
const allPosts = {
type: new GQL.GraphQLList(postType),
args: {
username: {
description: 'username of the user',
type: GQL.GraphQLString,
},
// An arg with the key limit will automatically be converted to a limit on the target
limit: {
type: GQL.GraphQLInt,
default: 10
},
// An arg with the key order will automatically be converted to a order on the target
order: {
type: GQL.GraphQLString
}
},
// use graphql-sequelize resolver with the Post model from database
resolve: resolver(Post)
}
I'm currently getting a Maximum call stack size exceeded
.我目前收到
Maximum call stack size exceeded
。 I assume because the resolver
in the queries are recursively getting details on posts and users infinitely.我假设是因为查询中的
resolver
无限递归地获取有关帖子和用户的详细信息。
Does anyone know of any way to put a depth limitation on the resolver?有谁知道有什么方法可以对解析器设置深度限制? Or is it just not possible to have a recursive query like this?
还是不可能有这样的递归查询?
You would have to remove the default scope from the included model as shown here like this:你将不得不从如图所示,包括模型删除默认的范围在这里是这样的:
Post.addScope('defaultScope', {
include: [{ model: User.scope(null), as: 'userObject' }],
}, { override: true })
User.addScope('defaultScope', {
include: [{ model: Post.scope(null), as: 'posts' }],
}, { override: true })
To support additional depth, you'd need to implement resolvers for the fields in question, for example:为了支持额外的深度,您需要为相关字段实现解析器,例如:
function resolve (user) {
if (user.posts) {
return user.posts
}
return user.getPosts()
}
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