Grafana dashboard: GraphQL join test
Description: Re. https://github.com/grafana/grafana/issues/31104 and GraphQL

For demonstrating issue https://github.com/grafana/grafana/issues/31104 with GraphQL datasource

{
  "__inputs": [],
  "__requires": [
    {
      "type": "grafana",
      "id": "grafana",
      "name": "Grafana",
      "version": "7.5.4"
    },
    {
      "type": "panel",
      "id": "table",
      "name": "Table",
      "version": ""
    }
  ],
  "annotations": {
    "list": [
      {
        "builtIn": 1,
        "datasource": "-- Grafana --",
        "enable": true,
        "hide": true,
        "iconColor": "rgba(0, 211, 255, 1)",
        "name": "Annotations & Alerts",
        "type": "dashboard"
      }
    ]
  },
  "editable": true,
  "gnetId": 14341,
  "graphTooltip": 0,
  "id": null,
  "links": [],
  "panels": [
    {
      "datasource": null,
      "fieldConfig": {
        "defaults": {
          "color": {
            "mode": "thresholds"
          },
          "custom": {
            "align": null,
            "filterable": false
          },
          "mappings": [],
          "thresholds": {
            "mode": "absolute",
            "steps": [
              {
                "color": "green",
                "value": null
              },
              {
                "color": "red",
                "value": 80
              }
            ]
          }
        },
        "overrides": []
      },
      "gridPos": {
        "h": 9,
        "w": 12,
        "x": 0,
        "y": 0
      },
      "id": 2,
      "options": {
        "frameIndex": 0,
        "showHeader": true
      },
      "pluginVersion": "7.5.4",
      "targets": [
        {
          "aliasBy": "",
          "annotationTags": "",
          "annotationText": "",
          "annotationTitle": "",
          "constant": 6.5,
          "dataPath": "station.timetable.nextArrivals",
          "endTimePath": "endTime",
          "groupBy": "",
          "queryText": "{\n  station:stationWithEvaId(evaId: 8000105) {\n    timetable {\n      nextArrivals {\n        platform\n        trainNumber\n      }\n    }\n  }\n}",
          "refId": "A",
          "timeFormat": null,
          "timePath": ""
        },
        {
          "aliasBy": "",
          "annotationTags": "",
          "annotationText": "",
          "annotationTitle": "",
          "constant": 6.5,
          "dataPath": "station.timetable.nextArrivals",
          "endTimePath": "endTime",
          "groupBy": "",
          "hide": false,
          "queryText": "{\n  station:stationWithEvaId(evaId: 8000107) {\n    timetable {\n      nextArrivals {\n        platform\n        trainNumber\n      }\n    }\n  }\n}",
          "refId": "B",
          "timeFormat": null,
          "timePath": ""
        }
      ],
      "title": "Panel Title",
      "transformations": [
        {
          "id": "seriesToColumns",
          "options": {
            "byField": "platform"
          }
        }
      ],
      "type": "table"
    }
  ],
  "schemaVersion": 27,
  "style": "dark",
  "tags": [],
  "templating": {
    "list": []
  },
  "time": {
    "from": "now-6h",
    "to": "now"
  },
  "timepicker": {},
  "timezone": "",
  "title": "GraphQL join test",
  "uid": "v-vkUB9Gk",
  "version": 1,
  "description": "Re. https://github.com/grafana/grafana/issues/31104 and GraphQL"
}