PG strange error: doesn't retrieve columns, but they are there!

[frederikhors]

I have a problem this with Postgres (PG dialect). But this is really strange to me.

ENTIRE REPRODUCTION HERE (also with Postgres database online): https://glitch.com/edit/#!/postgres-join-monster

If you click on "Show Live" button it opens Graphql Playground.

The schema, resolvers and query is the same as the Readme here: https://github.com/acarl005/join-monster-graphql-tools-adapter

Can you see the error in Playground?

When I query with:

query {
  user(id: 1) {
    id
    fullName
    email
    posts {
      id
      body
      numComments
      comments {
        id
        body
        userId
      }
    }
  }
}

it says:

{
  "data": {
    "user": null
  },
  "errors": [
    {
      "message": "column posts.userid does not exist",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "user"
      ],
      "extensions": {
        "code": "INTERNAL_SERVER_ERROR",
        "exception": {
          "name": "SequelizeDatabaseError",
          "parent": {
            "name": "error",
            "length": 104,
            "severity": "ERROR",
            "code": "42703",
            "position": "317",
            "file": "parse_relation.c",
            "line": "2876",
            "routine": "errorMissingColumn",
            "sql": "SELECT\n  \"user\".\"id\" AS \"id\",\n  \"user\".\"email\" AS \"email\",\n  \"posts\".\"id\" AS \"posts__id\",\n  (SELECT count(*) FROM comments where \"posts\".id = comments.postId) AS \"posts__numComments\",\n  \"user\".\"first_name\" AS \"first_name\",\n  \"user\".\"last_name\" AS \"last_name\"\nFROM users \"user\"\nLEFT JOIN posts \"posts\" ON \"user\".id = \"posts\".userId\nWHERE \"user\".id = 1"
          },
          "original": {
            "name": "error",
            "length": 104,
            "severity": "ERROR",
            "code": "42703",
            "position": "317",
            "file": "parse_relation.c",
            "line": "2876",
            "routine": "errorMissingColumn",
            "sql": "SELECT\n  \"user\".\"id\" AS \"id\",\n  \"user\".\"email\" AS \"email\",\n  \"posts\".\"id\" AS \"posts__id\",\n  (SELECT count(*) FROM comments where \"posts\".id = comments.postId) AS \"posts__numComments\",\n  \"user\".\"first_name\" AS \"first_name\",\n  \"user\".\"last_name\" AS \"last_name\"\nFROM users \"user\"\nLEFT JOIN posts \"posts\" ON \"user\".id = \"posts\".userId\nWHERE \"user\".id = 1"
          },
          "sql": "SELECT\n  \"user\".\"id\" AS \"id\",\n  \"user\".\"email\" AS \"email\",\n  \"posts\".\"id\" AS \"posts__id\",\n  (SELECT count(*) FROM comments where \"posts\".id = comments.postId) AS \"posts__numComments\",\n  \"user\".\"first_name\" AS \"first_name\",\n  \"user\".\"last_name\" AS \"last_name\"\nFROM users \"user\"\nLEFT JOIN posts \"posts\" ON \"user\".id = \"posts\".userId\nWHERE \"user\".id = 1",
          "stacktrace": [
            "SequelizeDatabaseError: column posts.userid does not exist",
            "    at Query.formatError (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/sequelize/4.38.0/node_modules/sequelize/lib/dialects/postgres/query.js:363:16)",
            "    at query.catch.err (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/sequelize/4.38.0/node_modules/sequelize/lib/dialects/postgres/query.js:86:18)",
            "    at tryCatcher (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/util.js:16:23)",
            "    at Promise._settlePromiseFromHandler (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/promise.js:512:31)",
            "    at Promise._settlePromise (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/promise.js:569:18)",
            "    at Promise._settlePromise0 (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/promise.js:614:10)",
            "    at Promise._settlePromises (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/promise.js:690:18)",
            "    at _drainQueueStep (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/async.js:138:12)",
            "    at _drainQueue (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/async.js:131:9)",
            "    at Async._drainQueues (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/async.js:147:5)",
            "    at Immediate.Async.drainQueues (/rbd/pnpm-volume/13dab6e7-982a-4e75-a7d2-4720db53e6c6/node_modules/.registry.npmjs.org/bluebird/3.5.2/node_modules/bluebird/js/release/async.js:17:14)",
            "    at runCallback (timers.js:810:20)",
            "    at tryOnImmediate (timers.js:768:5)",
            "    at processImmediate [as _immediateCallback] (timers.js:745:5)"
          ]
        }
      }
    }
  ]
}

If I change it from:

sqlJoin: (userTable, postTable) => ${userTable}.id = ${postTable}.userId,

to:

sqlJoin: (userTable, postTable) => ${userTable}.id = ${postTable}."userId",

it works. But there is another error after...

Where am I wrong?