https://stackoverflow.com/questions/65953252/grafana-timeseries-chart-from-mysql-json-data
https://stackoverflow.com/questions/54771946/grafana-sql-query-convert-string-to-number
- 曲线图,基于时序数据
SELECT UNIX_TIMESTAMP(created_at) as time_sec,
CAST(metric_value as SIGNED integer) as value,
'Metric Value' as metric
FROM lumenis_db.telemetry
WHERE $__timeFilter(created_at)