What would be the best way, for example, to display all tanks in which their temperature was 150 degrees and higher over the last 24 hours. This could then give a report of something and a bonus would be a showing which time periods it was 150 degrees and over. These are all actively in historian and have a similar tag structure with only a single indirect parameter differentiating them.
I’ve been racking my brain if this would be something done in a Report, Named query, or Transaction group, etc…? Thanks
Don’t know if its the best way. But, I would do it with the reporting module using nested queries using named queries.
I was thinking along those lines. I was trying to do a tag historian query which has all the built in power to span over all the tables (we have history split by months), then somehow query that query. But I don’t think that’s what nested queries do, I’m having trouble getting that to work.
The sub-query would be part of the nested query. If you don’t have someone who can write a query like that handy. Maybe you could do your Tag History Query then dump that into a data-set param. But, that might come with its own problem set. Say, if they are to large or what-not.
The best thing I ever did was concentrate on learning SQL properly.
Consider using your tag historian query to collect all the raw data you need, then use a script data source to reprocess that data into the nested data keys you need. Your report's charts and tables (and/or nested tables) would use the reprocessed data. This post might help you:
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