I have two tables (see attached spreadsheet for table data); the tables are joined by the wdic_mac column. The table wdic contains a number of devices that check-in regularly and upload data. The healthcheck table has a row added each time a device submits a status check to say "I'm here" with the date and time in the lastupdated column.
I want to create a view that shows when a device in the wdic table hasn't checked-in in the past 12 hours. I tried a left join (wdic to healthcheck) but I get no rows at all :-(
What I'm hoping for is a list of devices from wdic where there isn't a row in the healthcheck table containing a date/time in the past 12 hours.
May someone show me an example with the test data of how I may get the results I'm looking for please.
You may need to tinker with the data in the healthcheck table (delete some rows or adjust the date/time) to make it look like a device hasn't checked-in.
Hope this makes sense and thank you in advance for your help.