Wrong column name in predicates with connected fields #512
Description
Describe the bug
The following statement should translate Post.keys.user to postUserId
Amplify.DataStore.query(Post.self, where: Post.keys.user == Service.shared.userId()
However the following error occurs:
no such column: root.user in "select
"root"."id" as "id", "root"."createdTimestamp" as "createdTimestamp", "root"."imageUrl" as "imageUrl",
"root"."text" as "text", "root"."updatedTimestamp" as "updatedTimestamp", "root"."postUserId" as "postUserId",
"user"."id" as "user.id", "user"."bio" as "user.bio", "user"."createdTimestamp" as "user.createdTimestamp",
"user"."emailAddress" as "user.emailAddress", "user"."fullName" as "user.fullName", "user"."isEditable" as "user.isEditable",
"user"."isFollowing" as "user.isFollowing", "user"."profileImageUrl" as "user.profileImageUrl", "user"."updatedTimestamp" as "user.updatedTimestamp"
from Post as root
inner join User as user
on "user"."id" = "root"."postUserId"
where 1 = 1
and "root"."user" = ?"
Failed to retrieve posts: DataStoreError: The operation couldn’t be completed. (SQLite.Result error 0.)
Referring to a model
type User @model {
id: ID!
fullName: String!
emailAddress: String
bio: String
profileImageUrl: String
isFollowing: Boolean
following: [UserFollowing] @connection(name: "UserFollowing")
followers: [UserFollowers] @connection(name: "UserFollowers")
isEditable: Boolean
posts: [Post] @connection(name: "UserPosts")
createdTimestamp: Int!
updatedTimestamp: Int
}
type Post @model {
id: ID!
user: User! @connection(name: "UserPosts")
text: String
imageUrl: String
createdTimestamp: Int!
updatedTimestamp: Int
}
Amplify will generate the following:
Post.swift
// swiftlint:disable all
import Amplify
import Foundation
public struct Post: Model {
public let id: String
public var user: User
public var text: String?
public var imageUrl: String?
public var createdTimestamp: Int
public var updatedTimestamp: Int?
public init(id: String = UUID().uuidString,
user: User,
text: String? = nil,
imageUrl: String? = nil,
createdTimestamp: Int,
updatedTimestamp: Int? = nil) {
self.id = id
self.user = user
self.text = text
self.imageUrl = imageUrl
self.createdTimestamp = createdTimestamp
self.updatedTimestamp = updatedTimestamp
}
}
Post+schema.swift
// swiftlint:disable all
import Amplify
import Foundation
extension Post {
// MARK: - CodingKeys
public enum CodingKeys: String, ModelKey {
case id
case user
case text
case imageUrl
case createdTimestamp
case updatedTimestamp
}
public static let keys = CodingKeys.self
// MARK: - ModelSchema
public static let schema = defineSchema { model in
let post = Post.keys
model.pluralName = "Posts"
model.fields(
.id(),
.belongsTo(post.user, is: .required, ofType: User.self, targetName: "postUserId"),
.field(post.text, is: .optional, ofType: .string),
.field(post.imageUrl, is: .optional, ofType: .string),
.field(post.createdTimestamp, is: .required, ofType: .int),
.field(post.updatedTimestamp, is: .optional, ofType: .int)
)
}
}
as you can see post.user should have a target of postUserId however when using post.keys.user, the column cannot be found.
Solution:
To solve this issue, the following statement works:
Amplify.DataStore.query(Post.self, where: field("postUserId") == Service.shared.userId()
This does work, but without looking at the Post+schema, a user should not reasonably expect understand this, they should be able to look at the model to understand the connections, as the schema is really implementation details?