Alert Query Error - relation "metric_table" does not exist

I am attempting to set up an alert on a graph panel. There is a single query, “A”, on this panel. The alert rule is configured as shown:

The alert triggers despite having a value above the trigger. When I test the alert query there is the following error:

“tsdb.HandleRequest() response error &{pq: relation “metric_table” does not exist A 0xc0011477a0 [] []}”

Here is the full response from the test:

{
  "firing": true,
  "state": "pending",
  "conditionEvals": " = true",
  "timeMs": "47.684ms",
  "error": "tsdb.HandleRequest() response error &{pq: relation \"metric_table\" does not exist  A 0xc0011477a0 [] []}",
  "logs": [
    {
      "message": "Condition[0]: Query",
      "data": {
        "from": 1566943364587,
        "queries": [
          {
            "refId": "A",
            "model": {
              "format": "time_series",
              "group": [],
              "metricColumn": "none",
              "rawQuery": false,
              "rawSql": "SELECT\n  $__time(time_column),\n  value1\nFROM\n  metric_table\nWHERE\n  $__timeFilter(time_column)\n",
              "refId": "A",
              "select": [
                [
                  {
                    "params": [
                      "battery_level"
                    ],
                    "type": "column"
                  },
                  {
                    "params": [
                      "Battery Level"
                    ],
                    "type": "alias"
                  }
                ]
              ],
              "table": "positions",
              "timeColumn": "date",
              "timeColumnType": "timestamp",
              "where": [
                {
                  "name": "$__timeFilter",
                  "params": [],
                  "type": "macro"
                }
              ]
            },
            "datasource": {
              "id": 6,
              "name": "Teslamate"
            },
            "maxDataPoints": 0,
            "intervalMs": 0
          }
        ],
        "to": 1566943664587
      }
    }
  ]
}

What am I doing wrong?

What does this error mean? I am having the same problem.